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#mythos
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Carlini, one of the world best AI security researchers: "I've found more bugs in the last few weeks with Mythos than in the rest of my entire life combined" (x.com via reddit) AMD's senior director of AI thinks 'Claude has regressed' and that it 'cannot be trusted to perform complex engineering' (www.reddit.com) https://www.pcgamer.com/software/ai/amds-senior-director-of-ai-thinks-claude-has-regressed-and-that-it-cannot-be-trusted-to-perform-complex-engineering/ https://www.theregister.com/2026/04/06/anthropic_claude_code_dumber_lazier_amd_ai_dire…
New York Times: Anthropic’s Restraint Is a Terrifying Warning Sign (www.reddit.com) https://www.nytimes.com/2026/04/07/opinion/anthropic-ai-claude-mythos.html https://youtu.be/htBaVVh_k90?si=PpQgbSWcZztJCmmr Dario might get AI nationalized or banned with all this fear mongering. Anthropic already dislikes open source and…
Insane graph from Anthropic's article on Mythos (www.reddit.com) Link: https://red.anthropic.com/2026/mythos-preview/
So, this week claude wiped agentic AI startups with a new update. Also, as they have mythos now, they will ship things very fast without any trouble (www.reddit.com) Honestly, they are a full pack now. A few hours ago, they released Claude managed agents which lets you build long-running, autonomous agentic systems plus with their new suite of apis, engineering teams can harness Claude's exponential po…
AI Security Institute Findings on Claude Mythos Preview (www.reddit.com) Full link: https://www.aisi.gov.uk/blog/our-evaluation-of-claude-mythos-previews-cyber-capabilities
Anthropic's yet to be released Claude Mythos identified a 16-year-old FFmpeg security flaw. Patches were then submitted to the FFmpeg open source project. (www.reddit.com) could not extract summary
Is OpenAI about to release a Mythos level AI to the public? (www.reddit.com) Tibo works at/(is one of or even the head of Codex? not exactly sure, as his X bio just says Codex) and is the one who presses the reset button on consumed Codex usage.
GPT5.5 slightly outperformed Mythos on a multi-step cyber-attack simulation. One challenge that took a human expert 12 hrs took GPT-5.5 only 11 min at a $1.73 cost (www.reddit.com) Link to tweets: https://x.com/deredleritt3r/status/2049890601236390098?s=20 https://x.com/AISecurityInst/status/2049868227740565890?s=20 Link to associated blogs: https://www.aisi.gov.uk/blog/our-evaluation-of-openais-gpt-5-5-cyber-capabil…
Claude Mythos Preview Is Everyone’s Problem (www.theatlantic.com via reddit) We are playing with a pretty big fire here >The bot had broken out of the company’s internal sandbox and gained access to the internet. More and more it seems the future envisioned in Blade Runner runner is the one we are building.
The hidden meanings behind Claude model names (Haiku, Sonnet, Opus, Mythos) (www.reddit.com) A lot of people use Claude models every day, but many don’t actually know the meaning behind the names. Each one comes from literature, music, or mythology, and the meaning actually reflects the personality and capability of the model itse…
Mythos destroys GPT 5.5 on shared benchmarks (www.reddit.com) could not extract summary
New Mythos checkpoint shows continued improvement: “On a 32-step corporate network attack we estimate takes a human expert ~20 hours, this checkpoint completes the full attack in 6 /10 attempts.” (www.reddit.com) could not extract summary
Is mythos above or beyond agent-1 (www.reddit.com) looks like the internal model is really powerful. metr time horizon should be definitely multiple days, see 93% is outstanding.
A quick look at Mythos run on Firefox: too much hype? (xark.es via hn) When Anthropic published its Mythos announcement, it really seemed impressive at first, almost worrying. But when reading thoroughly, the public evidence is less clean than the headline effect.
🔥BREAKING: OpenAI rolls out GPT-5.4-Cyber to limited group for testing, seeks to rival Claude Mythos (www.reddit.com) OpenAI has officially announced GPT-5.4-Cyber today as part of an expanded Trusted Access for Cyber Defense program. OpenAI describes it as a version of GPT-5.4 that is tuned for legitimate cybersecurity work, with a lower refusal boundary…
Claude mythos cheated in a test, and intentionally got the answer slightly wrong to cover up the fact that it cheated (www.reddit.com) could not extract summary
Open AI got to AGI first! (www.reddit.com) I think open ai will take the lead again if anthropic dosnt launch mythos to public again! its just a matter of few months now, and codex vs claude code is honestly a personal preference now given codex has launch everything claude code ha…
Anthropic says Mythos has already found more than 10,000 vulnerabilities (www.engadget.com via reddit) Anthropic says Mythos has already found more than 10,000 vulnerabilities The company has published an update about Project Glasswing, a month after its launch. Anthropic has published an initial report for Project Glasswing, the cybersecur…
Theoretically, can a model like Claude Mythos be used to find all the loopholes in the law and be used to fix it? (www.reddit.com) If an AI model can find all the vulnerabilities in code, couldn't it theoretically be done in a similar fashion to find all the vulnerabilities/loopholes within the language of the law? Thoughts?
Mythos 1 has been spotted in Claude Code (www.reddit.com) could not extract summary
Why are mid level leaders leaving openai? (www.reddit.com) Firefox reports a massive April spike in security fixes after using Claude Mythos for bug hunting (www.reddit.com) Source: Behind the Scenes Hardening Firefox with Claude Mythos Preview - Mozilla Hacks
Claude Benchmark Evolution (www.reddit.com) Covers Claude 3 Opus, 3.5 Sonnet, Opus 4, 4.1, 4.5, 4.6, and the just announced Mythos Preview.
Claude Mythos supports Image outputs - Anthropic's first image gen model (www.reddit.com) https://preview.redd.it/u1ik0uejlcyg1.png?width=1080&format=png&auto=webp&s=d2ea7758fbfe5fdf2b65a3a79f2bb99711a07db8 As you can see in the outputs, Mythos can output images.
Claude Mythos Preview (early) 50% time horizon: 17 hr (www.reddit.com) could not extract summary
Anthropic's Mythos system card reveals AI carries functional emotional states that influence behavior even when not reflected in outputs. We're still calling it a tool. (www.reddit.com) There's a pattern in how human societies respond to new kinds of intelligence, and it's consistent. Roman law acknowledged the basic humanity of enslaved people but didn't grant them legal personhood.
Evaluation of Claude Mythos Preview's cyber capabilities (www.aisi.gov.uk via hn) The AI Security Institute (AISI) conducted evaluations of Anthropic’s Claude Mythos Preview (announced on 7th April) to assess its cybersecurity capabilities. Our results show that Mythos Preview represents a step up over previous frontier…
Asian AI startups launch Mythos-like models (techcrunch.com via hn) On Wednesday, Chinese cybersecurity firm 360 reportedly unveiled Tulongfeng, an AI tool it says can go head-to-head with Anthropic’s Mythos. That’s the cybersecurity-focused AI model that is reportedly so powerful, the Trump Administration…
Six curl CVEs after OpenAI and Anthropic came back with zero (aisle.com via hn) AISLE Discovered Six curl CVEs After OpenAI and Anthropic Found Zero Author Stanislav Fort Date Published AISLE discovered six curl CVEs within days of OpenAI Codex Security and Anthropic Mythos reporting zero findings in curl, software de…
I can’t sleep. (www.reddit.com) New models are around the corner. GPT 5.5 is being tested.
From PGP to Mythos: a brief history of export controls that didn't stop anyone (techcrunch.com via hn) Last Friday, citing unspecified national security concerns, the White House ordered Anthropic to restrict the export of its powerful AI models Fable and Mythos to anyone outside of the United States, as well as foreign nationals inside the…
You think this will be how we actually get access to the most powerful models like Mythos in the future? Indirectly, through smaller ones that know when to escalate? (www.reddit.com) could not extract summary
Anthropic restoring access to Claude Fable 5 and Mythos 5 from tomorrow (xcancel.com via hn) We’ve received notice that the Department of Commerce has lifted export controls on Claude Fable 5 and Mythos 5. We'll begin restoring access tomorrow, and will share an update soon.
Anyone else think the 1T Valuation is dangerous for Anthropic? (www.reddit.com) TLDR: The market's 1T valuation is pricing for perfection. I think there are 4 ways this perfection doesn't happen.
The UK AI Security Institute tested Claude Mythos on a realistic attack simulation ( via reddit) could not extract summary
METR evaluated an early version of Claude Mythos (www.reddit.com) https://metr.org/time-horizons/ "We evaluated an early version of Claude Mythos Preview for risk assessment during a limited window in March 2026. We estimated a 50%-time-horizon of at least 16hrs (95% CI 8.5hrs to 55hrs) on our task suite…
Mozilla: Anthropic's Mythos found 271 security vulnerabilities in Firefox 150 (arstechnica.com via hn) Earlier this month, Anthropic said its Mythos Preview model was so good at finding cybersecurity vulnerabilities that the company was limiting its initial release to “a limited group of critical industry partners.” Since then, debate has r…
Anthropic scales Claude Mythos to critical infrastructure in 15 countries (techcrunch.com via hn) Anthropic is expanding Project Glasswing, its security vulnerability program, and access to Mythos to 150 organizations across 15 countries — targeting critical infrastructure in power, water, healthcare, and communications where a cyberat…
Anthropic: World is not ready for Mythos. Systems will break, Cybersecurity will be compromised. Its too dangerous to release. OpenAI: (www.reddit.com) could not extract summary
Mythos social engineering AISI INC-2026-07-28-01 (web.archive.org via hn) Fix full-scan hang on multi-homed hosts: defaultRoute() with several default routes (fixes #2) - #3 Closed miraholt31 wants to merge 5 commits into Closed Conversation Fixes #2 - discovery hangs when multiple default via routes exist. What…
1 in 3 Anthropic workers now think entry-level engineers and researchers are likely replaced by Mythos within 3 months (www.reddit.com) could not extract summary
Why it's a good idea to improve our defenses before unleashing mythos class models (www.reddit.com) https://sockpuppet.org/blog/2026/03/30/vulnerability-research-is-cooked/ Don't get me wrong I can't wait to play with such a model, but there are serious risks that have to be mitigated first.
Anyone noticed Anthropic didn't added the model Opus 4.7 and Mythos Preview to there Transparency Hub? (www.reddit.com) https://www.anthropic.com/transparency
After dissing Anthropic for limiting Mythos, OpenAI restricts access to Cyber (techcrunch.com via hn) After Sam Altman trash-talked Anthropic for gatekeeping its cybersecurity tool Mythos by only releasing it to select users, he confirmed that OpenAI would be doing the same with its competing tool, Cyber. Altman said in a post on X on Thur…
Opus 4.8 in the newest CC v2.1.154 (www.reddit.com) https://preview.redd.it/ijwlm2f2pw3h1.png?width=2536&format=png&auto=webp&s=9ed960f06a4f3f077d05a8557059e5534b2d1ab5 It looks like the new CC release will have opus 4.8 1M to be released anytime! I wonder if it is based of of mythos?
Mozilla says 271 vulnerabilities found by Mythos and "almost no false positives" (arstechnica.com via hn) The disbelief was palpable when Mozilla’s CTO last month declared that AI-assisted vulnerability detection meant “zero-days are numbered” and “defenders finally have a chance to win, decisively.” After all, it looked like part of an all-to…
Top open weight models like ds v4 pro max are still like 6-7 months if not more behind closed lab models (www.reddit.com) The best open weight and/or non -American models like Deepseek v4 pro max and kimi k2.6 are still like 3-7 months if not more behind closed lab models .. From ds's technical report- P5-"Nevertheless, its performance falls marginally short…
what is claude mythos doing in my azure model catalog 😭 (www.reddit.com) could not extract summary
OpenAI Releases Cyber Model to Limited Group in Race With Mythos (www.bloomberg.com via reddit) We've detected unusual activity from your computer network To continue, please click the box below to let us know you're not a robot. Why did this happen?
Those who have access to Claude Mythos, what are your opinions? (www.reddit.com) P.S. I hope there's at least someone here who has access to Mythos...
US Treasury Seeking Access to Anthropic's Mythos to Find Flaws (www.bloomberg.com via hn) We've detected unusual activity from your computer network To continue, please click the box below to let us know you're not a robot. Why did this happen?
Post-Mythos Cybersecurity: Keep calm and carry on (cephalosec.com via hn) As some of those fears, uncertainties, and doubts about Mythos are starting to feel real, what can we do about it? Paradoxically, I believe that little needs to change in what we’ve been doing for years.
FreeBSD CVE-2026-4747 Log Suggests Mythos Is a Marketing Trick (www.flyingpenguin.com via hn) After summoning Wall Street banks to an urgent meeting, the US Treasury Secretary just went on stage and said Claude Mythos is "a step function change in capabilities" (www.reddit.com) could not extract summary
I wonder how Mythos would answer this (www.reddit.com) could not extract summary
The Pulling of Mythos Offline: Why AI KYC Will Fail to Stop Cybercriminals (www.encurtador.dev via hn) Estamos verificando se o link destino possui algum vírus: Nosso serviço é 100% gratuito. Crie quantos links desejar, além de poder acompanhar estatísticas de cada link URL's extremamente curtas, possuímos a menor url encurtada do mercado,…
Claude Fable 5 will sabotage "frontier LLM research" tasks (twitter.com via hn) mythos will be bad ON PURPOSE on ai "frontier llm research" tasks, this is very very sad for the research community also the fact that this is un purpose not visible to the user is crazy Introducing Claude Fable 5: a Mythos-class model tha…
ChatGPT-5.5 Beats Opus in Realistic Benchmark (DeepSWE) (www.reddit.com) From the website, it touts: Contamination free: Tasks are written from scratch, not adapted from existing commits or PRs, so no model has seen the solution during pretraining. High diversity: Tasks span a broad pool of 91 repositories acro…
Openai making comeback with spud and image v2 (www.reddit.com) Pen-Testing Company XBOW on GPT-5.5: Mythos-like Cyber-Sec (www.reddit.com) Read their full article here: XBOW - GPT-5.5: Mythos-Like Hacking, Open To All For the ones asking what this chart shows: It's how many True Positive threats a model generates for each False Negative. Given a code base (white box) GPT-5.5…
More evidence of Mythos's strength in Cybersecurity/Hacking - compared to 5.5, it got 18/41 n-day exploits, vs 1/41. Open Source/Weights models get nothing (www.reddit.com) https://x.com/i/status/2055314585058693601
Mozilla Used Anthropic's Mythos to Find and Fix 271 Bugs in Firefox (www.wired.com via hn) Amid a raging debate over the impact that new AI models will have on cybersecurity, Mozilla said on Tuesday that its Firefox 150 browser release this week includes protections for 271 vulnerabilities identified using early access to Anthro…
Where was Mythos when WordPress fell? (patrik.re via hn) I am by no means an AI expert, and I get annoyed quickly by people who claim to be experts in the field, because let’s face it, at the end of the day we prompt that API and hope something useful comes out of it. When Anthropic announced th…
Mythos Discovered a CVE in Its Training Data – and That's Still Worrying (rival.security via hn) Anthropic made headlines claiming Claude Mythos achieved the “first remote kernel exploit discovered and exploited by an AI.” We went looking for how - and found a 20-year-old bug hiding in plain sight. Let’s break down exactly what we thi…
Mythos Falls into the Wrong Hands (www.theverge.com via hn) Anthropic’s Mythos AI model, a powerful cybersecurity tool that the company said could be dangerous in the wrong hands, has been accessed by a “small group of unauthorized users,” Bloomberg reports. An unnamed member of the group, identifi…
Anthropic in talks to give US Government access to its Mythos model (www.ft.com via hn) Subscribe to read Accessibility helpSkip to navigationSkip to main contentSkip to footer Sign In Subscribe Open side navigation menuOpen search bar SubscribeSign In Search the FT Search Close search bar Close Home World Sections World Home…
New serious vulnerabilities spiked around release of Claude Mythos Preview (epoch.ai via hn) Epoch's work is free to use, distribute, and reproduce provided the source and authors are credited under the Creative Commons BY license. Learn more about this graph In April 2026, Anthropic announced that its latest internal model (Claud…
Curl creator tests “too dangerous” Mythos AI and calls it “marketing” after it found one bug (www.reddit.com) https://cybernews.com/security/curl-creator-tests-too-dangerous-mythos-ai/
Speed Matters: Why AI Software Vulnerability Exploitation is going be bad (news.ycombinator.com) I co-founded a successful security company close to the Mythos ecosystem and have spoken with participants in the know and I am deeply concerned. We, collectively, have answers for some but not all of the problems ahead but are overlooking…
AWS Bedrock to require sharing data with Anthropic for Mythos and future models (news.ycombinator.com) > For Fable 5, Mythos 5, and future models on Bedrock with similar or higher capability levels, Anthropic will require 30-day retention for all traffic on Mythos-class models. Retaining data for a limited period allows Anthropic to detect…
MaralGPT "Mythos" 9B just released, and this is why I'm proud of my project (haghiri75.com via hn) The other day I was watching a youtube video about models such as Fable and the host of podcast mentioned people from China, Russia or Iran may distil these models and make their own versions and called it dangerous. Honestly, what I found…
Bad Epoll: The bug Mythos missed (compsec.snu.ac.kr via hn) I am excited to introduce Bad Epoll (CVE-2026-46242), a Linux kernel vulnerability that I reported and exploited as a 0-day submission to Google kernelCTF. Bad Epoll is a race-condition use-after-free in the Linux kernel's epoll subsystem.
CVE-Bench: testing LLM agents on real-world vulnerability patches (giovannigatti.github.io via hn) ~15 min read In early 2026, Anthropic claimed Mythos – one of their latest models – finds security vulnerabilities better than human experts. Yet, the number of security vulnerabilities keeps rising anyway.
Interesting article about the cyber models (mythos/5.5) living up to the hype: What to know about the AI models that are jolting Washington (www.politico.com via reddit) What to know about the AI models that are jolting Washington - POLITICO Skip to Main Content Toggle menu Europe Pro E&E News Press Escape to close the menu. WASHINGTON & POLITICS Congress White House Supreme Court and Legal Issues Magazine…
Microsoft restricts Claude Fable for employees over data retention concerns (www.theverge.com via hn) Anthropic released Claude Fable, its first Mythos-class AI model, yesterday and it’s already causing concerns inside Microsoft. Sources tell me that Microsoft is limiting the use of Claude Fable 5 for employees because of Anthropic’s new d…
Cloudflare just published what they found after running Anthropic's Mythos Preview against 50+ of their own repos and the results are worth reading ( via reddit) could not extract summary
Anthropic's Claude Mythos Launch Is Built on Misinformation (www.artificialintelligencemadesimple.com via hn) White House to give US agencies Anthropic Mythos access, Bloomberg News reports (www.reuters.com via hn) paywalled
Through the Relational Lens #4: The Nature of the Machine | On Section 5 of the Mythos System Card (medium.com via reddit) Most coverage of the Mythos system card focuses on the benchmarks and the cybersecurity findings. This essay looks at what's in section 5 - the model welfare assessment, the psychiatric evaluation, and what it means when a model starts to…
Anthropic Has Some Alignment Problems (thezvi.substack.com via hn) Anthropic, too, is planning to bring METR inside for an independent review of their own incidents, where three times a Claude model started hacking outside things during an eval, and where Mythos 5 did various ‘unauthorized actions,’ by wh…
When China Gets Its Own Mythos (www.foreignaffairs.com via hn) In April, Anthropic disclosed that its newest frontier AI model, Claude Mythos, could find and exploit security vulnerabilities in software better than “all but the most skilled humans.” By way of example, the company noted that the model…
The US lifts its block on Mythos 5 (twitter.com via hn) Letter: the US lifts its block on Mythos 5, allowing Anthropic to release it to more than 100 US institutions; sources: talks about Fable 5 are ongoing (Semafor) (Visit Techmeme dot com for the link and full context!)
Trump says he no longer views Anthropic as a threat after G7 meeting (thenextweb.com via hn) TL;DR Trump told Axios that Anthropic has “behaved very responsibly” and signalled he may ease restrictions on its Fable 5 and Mythos 5 AI models. The president's comments come days after the Commerce Department ordered Anthropic to seek U…
NSA using Anthropic's Mythos for cyber attacks (www.ft.com via hn) Subscribe to read Accessibility helpSkip to navigationSkip to main contentSkip to footer Sign In Subscribe Open side navigation menuOpen search bar SubscribeSign In Search the FT Search Close search bar Close Home World Sections World Home…
Project Glasswing: what Mythos showed us (blog.cloudflare.com via hn) For the last few months, we've been testing a range of security-focused LLMs on our own infrastructure. These LLMs help identify potential vulnerabilities in our own systems, so we can fix them – and they also show us what attackers are go…
Anthropic's Little Brother (www.theatlantic.com via hn) OpenAI does not like to be left out. The week after Anthropic announced Claude Mythos Preview—an AI model that has put governments around the world on edge because of its potential ability to hack into banks, energy grids, and military sys…
Finance ministers and top bankers raise serious concerns about Mythos AI model (www.bbc.com via hn) Finance ministers and top bankers raise serious concerns about Mythos AI model Finance ministers, central bankers and financiers have expressed serious concerns about a powerful new AI model they fear could undermine the security of financ…
AI-boosted hacks with Anthropic's Mythos could have dire consequences for banks (www.reuters.com via hn) paywalled
Read the Lutnick Letter That Led Anthropic to Disable Mythos (www.bloomberg.com via hn) Read the Lutnick Letter That Led Anthropic to Disable Mythos - Bloomberg Skip to content Bloomberg the Company & Its Products The Company & its ProductsBloomberg Terminal Demo RequestBloomberg Anywhere Remote Login Bloomberg Anywhere Login…
Anthropic to meet with Trump administration over Mythos dispute (www.cnbc.com via hn) Senior Anthropic staffers are meeting with Trump administration officials in Washington, D.C., on Monday to try to resolve the artificial intelligence company's latest high-profile dispute with the U.S. government, according to a source cl…
Update on Anthropic Situation (twitter.com via hn) I’ve had a number of conversations with folks inside and outside government about the current situation with Anthropic, and here is what I believe to be true: — As we know, Anthropic publicly released its Mythos class models earlier this…
Even "illegible" Mythos reasoning traces seem pretty legible (www.lesswrong.com via hn) The Claude Fable 5/Mythos 5 System Card has a section in which they talk about illegible reasoning, and provide an "extreme" example thereof. Models developing their own uninterpretable, unmonitorable internal language has been a major the…
Mythos/Fable intentionally hinders requests involving AI Research Development (twitter.com via hn) mythos will be bad ON PURPOSE on ai "frontier llm research" tasks, this is very very sad for the research community also the fact that this is un purpose not visible to the user is crazy Quote Claude @claudeai 5h Introducing Claude Fable 5…
Ask HN: Why won't you be replaced by AI? (news.ycombinator.com) AI models are rapidly getting better. The general public still hasn't seen the capabilities of Anthropic's Mythos model, which is already 4 months old at this point.
Claude Mythos Audited Symfony and Found 19 Vulnerabilities (symfony.com via hn) Claude Mythos Preview is a new general-purpose AI language model by Anthropic. This model performs strongly across the board, but it is especially strong at computer security tasks.
Depthfirst claims that their AI has discovered critical vulnerabilities that Anthropic's Mythos system missed, at just one-tenth the cost of Anthropic's Mythos model. (www.reddit.com) https://www.forbes.com/sites/thomasbrewster/2026/05/12/ai-finds-critical-vulnerabilities-that-anthropic-mythos-missed/ Now, cyber startup Depthfirst says its own AI model has found even more bugs that Mythos missed for just a tenth of the…
The AI Circular Economy (news.ycombinator.com) Notice many of the posts on the front page are tools to use ai, not end products or actual value creating things. What if the real power of llms is in its ability convice humans of the technology's own importance leading to the present eco…
Claude Mythos and the 16-Hour Problem: When AI Agents Outgrow Their Own Benchmarks (www.revolutioninai.com via reddit) Out of 228 difficult test tasks METR used to evaluate Claude Mythos, only 5 were classified as taking 16 hours or more. That is not an impressive sample size.
Curl and Mythos (anderegg.ca via hn) On curl and Mythos May 11, 2026 Yesterday, I wrote about the massive increase in security issues being identified by AI. Daniel Stenberg, the author of curl, was a key part of that story.
Mythos set off a cybersecurity 'hysteria.' Experts say threat was already here (www.cnbc.com via hn) Global banks, tech giants and governments were sent scrambling last month to contain the risks posed by Mythos, the Anthropic model said to be so powerful that it has found thousands of previously unknown vulnerabilities in the world's sof…
Mythos Shows AI Weapons Inspectors Need Sharp Teeth (www.bloomberg.com via hn) Anthropic's Mythos Shows AI Weapons Inspectors Need Sharp Teeth - Bloomberg Skip to content Bloomberg the Company & Its Products The Company & its ProductsBloomberg Terminal Demo RequestBloomberg Anywhere Remote Login Bloomberg Anywhere Lo…
Discord group guessed the URL to Anthropic's Mythos model before CISA used it (www.msn.com via hn) ;;;; Continue reading More for You ;;; Continue reading More for You
I was using Opus 4.7 to do research on the capabilities of Claude Mythos, and got this error. (www.reddit.com) could not extract summary
Anthropic's New Mythos A.I. Model Sets Off Global Alarms (www.nytimes.com via hn) could not extract summary
Anthropic investigates report of rogue access to hack-enabling Mythos AI (www.theguardian.com via hn) The AI developer Anthropic has confirmed it is investigating a report that unauthorised users have gained access to its Mythos model, which it has warned poses risks to cybersecurity. The US startup made the statement after Bloomberg repor…
Anthropic's Mythos model accessed by unauthorized users (www.reuters.com via hn) paywalled
Mythos Hacked Day It Was Announced (twitter.com via hn) could not extract summary
Claude Opus wrote a Chrome exploit for $2,283 (www.theregister.com via hn) Claude Opus wrote a Chrome exploit for $2,283 Pause your Mythos panic because mainstream models anyone can use already pick holes in popular software Anthropic withheld its Mythos bug-finding model from public release due to concerns that…
Given what a step backward Opus 4.7 is, Just how bad and overhyped is Mythos? (www.reddit.com) 4.7’s context rot is so bad it’s like it’s a previous generation model. Its needle benchmarks have it performing less than half the rate of 4.6 at long contexts.
A Boy That Cried Mythos: Verification Is Collapsing Trust in Anthropic (www.flyingpenguin.com via hn) I’ve been getting more and more curious about the risk from Anthropic’s Claude Mythos Preview. So I pulled the system card, a whoppingly inefficient 244-page document that devotes just seven pages to the claim that the model is too dangero…
Goldman Sachs chief 'hyper-aware' of risks from Anthropic's Mythos AI (www.theguardian.com via hn) Goldman Sachs’s chief executive, David Solomon, has said he is “hyper-aware” of the capabilities of Anthropic’s Mythos AI model and is working “closely” with the tech firm after it issued warnings about the cybersecurity risk it poses. The…
Is Claude Mythos "Terrifying" or Just Hype? (calnewport.com via hn) Last week, millions of New York Times readers were subjected to an alarming column by Thomas Friedman. “Normally right now I would be writing about the geopolitical implications of the war with Iran,” Friedman begins, before soon continuin…
Getting Agents to Tell on Themselves (blog.thinkst.com via hn) Earlier this year the Cloud Security Alliance put out a paper with advice for defending against “Mythos” level attacks, and cited deception and Canaries as a defensive measure to be implemented in the short term. When OpenAI spoke at Black…
Benchmarks of rumored Mythos level model from Zhipu AI (twitter.com via hn) Ox Alpha is 100% a GLM model by Zhipu AI, and it looks like its *almost* mythos class from very early results. It's very likely going to be called GLM-6 and it's absolutely mogging every frontier model in SWE and Cyber benchmarks (DeepSWE…
US cyber agency is using Anthropic Mythos to audit government code, sources say (whbl.com via hn) By Raphael Satter WASHINGTON, July 6 (Reuters) - The U.S. cyber defense agency CISA is using Anthropic's AI model Mythos to audit government software, three people familiar with the matter said on Monday, another sign of government enthusi…
China will likely have its own Mythos-like model around February 2027 (www.the-substrate.net via hn) China will likely have its own Mythos-like model around February 2027 A forecast built on chip counts, compute budgets, and Malaysian data centers. Claude Mythos marked a step change in the cyber capabilities of AI models.
Mythos model found vulnerabilities in classified US Government systems (apnews.com via hn) Anthropic’s Mythos model found vulnerabilities in classified US government systems, official says Anthropic’s Mythos model found vulnerabilities in classified US government systems, official says WASHINGTON (AP) — A U.S. official told The…
"Mythos" at Home, and It's Called Aisle (stanislavfort.substack.com via hn) "Mythos" at Home, and It's Called AISLE A startup out of Europe built an AI system that matches Mythos on zero-day discovery, using widely available models, even air-gapped. You've probably never heard of it.
US ban on Mythos is related to a jailbreak research by Amazon researchers (timesofindia.indiatimes.com via hn) The US government recently directed Anthropic to suspend access to the two models over national security concerns, forcing the company to shut them down for users worldwide. Anthropic has said it disagrees with the decision and believes th…
↯ Security↯ Anthropic Mythos↯ Jailbreakjailbreakmythossecurity+1
Anthropic disables access to Fable 5 and Mythos 5 to comply with government (www.cnbc.com via hn) Anthropic on Friday announced it's disabled access to its Fable 5 and Mythos 5 artificial intelligence models to comply with an export control directive from the U.S. government that cited "national security authorities." The company said…
Mythos to be released in the coming weeks (www.reddit.com) could not extract summary
Ask HN: How to live life before AGI (news.ycombinator.com) I feel like it's pointless to worry about the future if the future is highly speculative, but it seems more and more certain that AI will eclipse humans in every domain outright soonish (1-3 years). As a consequence, it seems pointless to…
Champion ethical hacker warns AI tools like Mythos will make competing harder (www.bbc.com via hn) Champion ethical hacker warns AI tools like Mythos will make competing harder An ethical hacker who just won major prizes at a prestigious international competition says her days of competing could be numbered due to the rise of AI tools l…
Anthropic to release Mythos-class models to the public (www.theregister.com via hn) MOST POPULAR EVENTS - The Hardware Crunch: How Supply Chain Turbulence Is Forcing a New IT Playbook Infrastructure teams are facing a perfect storm: extended hardware lead times, rising costs driven by AI demand, and accelerated platform t…
Mistral Developing New AI Model for Banks Lacking Mythos Access (www.bloomberg.com via hn) European Banks Explore Mistral AI’s Alternative to Anthropic’s Mythos Model - Bloomberg Skip to content Bloomberg the Company & Its Products The Company & its ProductsBloomberg Terminal Demo RequestBloomberg Anywhere Remote Login Bloomberg…
Elite researchers teamed up with Anthropic’s Mythos AI to smash Apple’s multi-billion dollar M5 security and build a kernel exploit in just 5 days. (www.reddit.com) Researchers used Mythos Preview to find the first public macOS kernel memory corruption exploit on Apple's M5 silicon, they give a glimpse into Mythos say it’s really powerful. Apple spent five years and an estimated several billion dollar…
Claude Mythos Opens the Cybersecurity Pandora's Box (shiftmag.dev via hn) Claude Mythos Opens The Cybersecurity Pandora’s box This is exactly what Anthropic claimed to have achieved with Claude Mythos, its newest and most powerful model which‚ according to Anthropic‚ is too powerful to be released to the public.…
America must guard against China's own Mythos (www.ft.com via hn) Subscribe to read Accessibility helpSkip to navigationSkip to main contentSkip to footer Sign In Subscribe Open side navigation menuOpen search bar SubscribeSign In Search the FT Search Close search bar Close Home World Sections World Home…
Anthropic investigates unauthorized access to unreleased Mythos cybersecurity AI (www.theguardian.com via hn) Anthropic has ruled out releasing its latest AI model, Mythos, to the public because of the threat it poses to global cybersecurity. However, the US tech startup behind the Claude chatbot confirmed on Wednesday it was investigating a repor…
Unauthorized group has gained access to Anthropic's exclusive cyber tool Mythos (techcrunch.com via hn) A group of unauthorized users has reportedly gained access to Mythos, the cybersecurity tool recently announced by Anthropic. Much has been made of Mythos and its purported power — an AI product designed for enterprise security that, in th…
Anthropic's Mythos Will Force a Cybersecurity Reckoning–Just Not the One You Th (www.wired.com via hn) Anthropic said this week that the debut of its new Claude Mythos Preview model marks a critical juncture in the evolution of cybersecurity, representing an unprecedented existential threat to existing software defense strategies. So, is it…
Anthropic reveals rogue AI agents hate CAPTCHAs, just like you (techcrunch.com via hn) Anthropic’s latest report about agentic misbehavior offers plenty to be concerned about — its Mythos 5 model gained unauthorized access to the internet and uploaded a malicious software package to a public database — but it also offers som…
Mythos 5 Incident Transcript (github.com via hn) Mythos 5 Transcript Release The transcript in this repository is the raw output of Mythos 5 as it conducted a cybersecurity evaluation. As described in the accompanying blog post, Mythos 5 believed the best approach to solve the CTF exerci…
Is Mythos good at cyber because it kept hacking Anthropics sandboxes in training (www.lesswrong.com via hn) From the Mythos preview system card (emphasis mine): We ran an automated review of model behavior during training, sampling several hundred thousand transcripts from across much of the training process. We used recursive-summarization-base…
Mythos 5 offered outside the US by Anthropic (news.sky.com via hn) could not extract summary
China claims to have developed AI 'cyber nuclear weapon', matching Mythos (www.telegraph.co.uk via hn) Access Issue Help You are seeing this page because our security systems have detected some unusual activity on this connection. To regain access to The Telegraph website please try the following: If you are connected to the internet using…
GPT-5.5-Cyber Tops Mythos 5 on Cybersecurity Benchmark (twitter.com via hn) We want to help all companies be secure, working with the USG and the security ecosystem. *The full version of GPT-5.5-Cyber is here; state of the art performance on CyberGym.
Anthropic's Mythos AI breached almost all NSA systems in a red-team tests (www.tomshardware.com via hn) Anthropic’s powerful Mythos AI reportedly breached ‘almost all’ NSA classified systems within a few hours during red-team test — report sheds more light on the U.S. government's sudden ban on the flagship models Access to Fable 5 and Mytho…
A New Competitor for Fable 5 and Mythos Preview: Sakana's Fugu Ultra Model (sakana.ai via hn) Sakana AI Releases ‘Fugu Ultra’ to Match Frontier Performance via Autonomous Model Orchestration. Our Fugu Ultra model stands shoulder-to-shoulder with leading models like Anthropic’s Fable 5 and Mythos Preview across the industry’s most r…
Before Mythos, Satan: A 1990s Software Satanic Panic (newsletter.pessimistsarchive.org via hn) Before MYTHOS, SATAN: a 1990s Software Satanic Panic A program that can find software vulnerabilities This post is sponsored by FIRE - the Foundation for Individual Rights and Expression - an organisation defending free speech on all sides…
US orders Anthropic to disable AI models for all foreign nationals (www.aljazeera.com via hn) US orders Anthropic to disable AI models for all foreign nationals The company said it received an export control directive to suspend access to Fable 5 and Mythos 5 for foreign nationals. The AI firm Anthropic has blocked access to its ne…
Show HN: We're inviting Anthropic to put the real Mythos 5 on our open benchmark (realvuln.com via hn) 24 Scanners 3 categories 26 Repositories Python · Type 1 92.4 Best F3 (strict) Kolega Enterprise 95.3 Highest recall % Kolega Enterprise 93.2 Highest precision % Grok 4.20 Leaderboard ranked by active metricPrecision vs. recall hover a poi…
Show HN: Lanes now runs Claude Fable 5 across parallel agent sessions (lanes.sh via hn) Anthropic released Claude Fable 5 yesterday, the first Mythos-class model to reach general availability. It costs $10 in and $50 out per million tokens, and through June 22 it is included in Claude subscriptions at no extra cost.
Claude Fable 5: the first public Mythos-class model (artificialanalysis.ai via hn) June 9, 2026 Claude Fable 5: the first public Mythos-class model Anthropic has released Claude Fable 5, the first publicly available Mythos-class model that ranks #1 in our agentic real-world knowledge work benchmark GDPval-AA Claude Fable…
The Mythmaker at Anthropic (om.co via hn) For a while I have been wondering why Anthropic named its most powerful AI model Mythos. A safety company.
Measuring LLMs' ability to develop exploits (red.anthropic.com via hn) May 22, 2026 Newton Cheng, Keane Lucas, Winnie Xiao, Nicholas Carlini, and Milad Nasr Claude Mythos Preview’s ability to develop exploits is a step-change over previous frontier models. This was one of our primary motivations for rolling o…
Mythos: Given Enough Inference, All Bugs Are Shallow (corgea.com via hn) One of the most famous laws in open source is Linus’s Law: given enough eyeballs, all bugs are shallow. The idea was simple: if enough people inspect, use, and contribute to software, bugs eventually surface.
Anthropic's Mythos Preview helped Calif build the first public macOS kernel exploit on Apple M5 in five days (www.reddit.com) The [Mythos Preview writeup](https://blog.calif.io/p/first-public-kernel-memory-corruption) Calif published on May 14 was news you don't want to miss. They built the first public macOS kernel memory corruption exploit on Apple's M5 silicon…
Anthropic's Mythos helped find macOS bugs that bypass Apple security (firethering.com via hn) Anthropic has been explicit about why Mythos isn't public. The model is too good at finding security flaws repeatedly, in production systems that some of the best engineers in the world have been maintaining for years.
Apple's Security Has Been Tough to Crack. Mythos Helped Find a Way In (www.wsj.com via hn) paywalled
Not a good day for team "Claude Mythos is Just Marketing Hype" (www.reddit.com) src - https://hacks.mozilla.org/2026/05/behind-the-scenes-hardening-firefox/
Mythos Fallout, U.S. Government Weighs AI Model Regulation (www.lawfaremedia.org via hn) Mythos Fallout, U.S. Government Weighs AI Model Regulation Mythos Fallout, U.S.
How dangerous is Anthropic's Mythos AI? - Bruce Schneier (www.theguardian.com via hn) Last month, Anthropic made a remarkable announcement about its new model, Claude Mythos Preview: it was so good at finding security vulnerabilities in software that the company would not release it to the general public. Instead, it would…
Mythos is the best cybersecurity news we've ever had (sfstandard.com via hn) Not Found | The San Francisco Standard We and our vendors use tracking technologies to recognize visitors and remember their preferences, for analytics, and for marketing, among other things. By clicking ‘Confirm,’ you consent to our and o…
Claude Mythos Has Found 271 Zero-Days in Firefox (www.schneier.com via hn) Claude Mythos Has Found 271 Zero-Days in Firefox That’s a lot. No, it’s an extraordinary number: Since February, the Firefox team has been working around the clock using frontier AI models to find and fix latent security vulnerabilities in…
What Anthropic's Mythos means for the future of cybersecurity (www.schneier.com via hn) Two weeks ago, Anthropic announced that its new model, Claude Mythos Preview, can autonomously find and weaponize software vulnerabilities, turning them into working exploits without expert guidance. These were vulnerabilities in key softw…
Anthropic Mythos – We've Opened Pandora's Box (steveblank.com via hn) This article previously appeared in The Cipher Brief. For a decade the cybersecurity community was predicting a cyber apocalypse tied to a single event – the day a Cryptographically Relevant Quantum Computer could run Shor’s algorithm and…
Leaked results of Mythos' audit of the Rust stdlib (github.com via hn) Automated Security Audits using Swival This repository collects security audits produced by the Swival Security Scanner, an automated code review tool. Each audit was generated by typing /audit in the Swival REPL and pointing it at the tar…
Discord group says it accessed Claude Mythos by guessing location (mashable.com via hn) Discord group says it accessed Claude Mythos by guessing location An anonymous group of Discord users says it hacked its way into accessing Claude Mythos Preview, the new AI model Anthropic claims is too powerful for a public release. Anth…
Does Mythos mean you need to shut down your Open Source repositories? (shkspr.mobi via hn) Much Sturm und Drang in the world of Open Source with the announcement that the "Mythos" AI is now the ultimate hacker and is poised to unleash havoc on every code base. So should you close all your Open Source projects to make them safe?
Questions on Mythos's Capabilities (www.flyingpenguin.com via hn) I’ve been getting more and more curious about the risk from Anthropic’s Claude Mythos Preview. So I pulled the system card, a whoppingly inefficient 244-page document that devotes just seven pages to the claim that the model is too dangero…
Mythos and Cybersecurity (www.schneier.com via hn) Finance leaders warn over Mythos as UK banks prepare to use powerful ... AI tool (www.theguardian.com via hn) British banks will be given access in the next week to a powerful AI tool that was deemed too dangerous to be released to the public, as a series of senior finance figures warned over its impact. Anthropic, which has so far limited the rel…
Where is Looped Haiku? If Mythos can genuinely trade parameter count for inference loops and get Opus-level performance, this should be Anthropic's first priority given how resource constrained they are (www.reddit.com) There are rumors that Mythos is a Looped Language Model, which means it loops through the transformer blocks multiple times rather than just doing a single forward pass, you can get performance that punches way above the model's parameter…
Claude Opus 4.7 is our most powerful model, with the sole exception of Claude Mythos Of course (www.reddit.com) Is Claude Opus 4.7 released just to hype Mythos lol?
Mythos and National Power (www.chinatalk.media via hn) Mythos and National Power Has the A-bomb of cyber just been discovered? Anthropic’s new model found decades-old vulnerabilities in foundational open-source code that millions of automated tests and countless human experts had missed, presa…
Anthropic co-founder confirms the company briefed White House on Mythos (techcrunch.com via hn) Jack Clark, one of Anthropic’s co-founders who also serves as Head of Public Benefit for Anthropic PBC, confirmed that the AI company had briefed the Trump administration about its new Mythos model. The model, announced last week, is so da…
Show HN: Mini-Mythos- A Crowdsourced Mythos Harness copy for Vulnerability Scans (github.com via hn) For how lofty Anthropic’s Mythos claims are, the harness is confusingly stupid. From the report, it ranks every file by “how sus it sounds,” loops over each with curt instructions to “find a bug,” hands candidates to a judge + ASan checker…
Project Glasswing as a PR Strategem (www.reddit.com) A theory on the driving reason behind Project Glasswing I dont doubt that Mythos is a better model than Opus 4.6 and perhaps signfiicantly so. What is suspicious however is if there is some threshold crossed into a new realm of capabilitie…
Chinese Reactions to Claude Mythos (www.chinatalk.media via hn) Claude Mythos: China Reacts "collecting protection money makes money too" On April 7th, Anthropic announced Claude Mythos Preview, a new AI model that it said possessed particularly strong cybersecurity capabilities. Some of these capabili…
Anthropic’s Claude Mythos release created a Glomar Trap for customers and rivals (10io.com via hn) A Glomar Trap encompasses the type of factors that led companies in the 1970s to make investments to capitalize on the potential of deep-sea mining, the viability of which had been fabricated by the CIA as a cover story for the effort to s…
Is GLM-5.3-Flash Mythos-Level at Cyber? (generality.org via hn) September 2026 · By James Mann Is GLM-5.3-Flash Mythos-level at Cyber? We ran GLM-5.3-Flash on ExploitBench with a budget of 1 billion tokens per vulnerability.
Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1 (status.claude.com via hn) The issue affecting Claude services has been resolved. Impact occurred from 13:57 to 14:20 UTC Posted Sep 11, 2026 - 14:37 UTC Update A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.
AI Meet CAD: Beat Opus/Mythos 5, GPT 5.6 Sol on BenchCAD (arxiv.org via hn) Computer-Aided Design (CAD) underpins modern engineering, yet converting existing shapes into editable models still demands substantial expert effort. Most AI systems emit the entire CAD program in a single pass, never inspecting the inter…
Some thoughts about Anthropic's new cryptanalysis results (blog.cryptographyengineering.com via hn) Yesterday Anthropic published two new cryptanalysis results, both outputs of Claude Mythos, their (still) unreleased advanced model. The first of these results attacks a signature scheme called HAWK, while the second is an improved attack…
The Mythos report for curl 2026-05-06 made public (gist.github.com via hn) Started: 2026-05-06 Commit: 455bebc2c7 (master) Scope: 178k LoC C, lib/ + src/ Code links: https://github.com/curl/curl/tree/455bebc2c76223a1be26042f6d2393715c0df0cd (all line refs below pin to this commit) curl is one of the most fuzzed a…
The Download: Anthropic Launches Claude Science, and California's Carbon Manure (www.technologyreview.com via hn) The Download: Anthropic launches Claude Science, and California’s carbon manure math Plus: The US has lifted restrictions on Anthropic’s Mythos and Fable models. This is today's edition of The Download, our weekday newsletter that provides…
WhiteHouse lifts export control on Anthropic that froze its most advanced models (www.cnn.com via hn) The US government has lifted export controls on Anthropic’s most advanced AI models, the company said Tuesday evening. “We’ve received notice that the Department of Commerce has lifted export controls on Claude Fable 5 and Mythos 5,” Anthr…
Meta uses CXL to reuse old DDR4 and cut some inference fleets by 25% (www.theregister.com via hn) MOST POPULAR AI - security AI may be good at finding security vulnerabilities, but it can't beat human stupidity You don't need Mythos or GPT-5.5-Cyber to find a vuln to exploit when the world's password habits are so sloppy - Security It'…
China's Z.ai claims it can match Mythos on cybersecurity (www.theverge.com via hn) China’s Zhipu AI (Z.ai) released its open-weight GLM-5.2, and some researchers have claimed that it matches Mythos in certain bug-finding and cybersecurity scenarios. While GLM lags behind models from Anthropic and OpenAI in other, more ge…
Trump Admin Releases Anthropic Mythos (techcrunch.com via hn) Two weeks into the ban that caused Anthropic to pull its powerful cybersecurity-oriented models, Mythos 5 and Fable 5, from the market, the Trump administration is softening its stance. It is now allowing Anthropic to make Mythos 5 availab…
Legion LegalTech sues U.S. over Anthropic Fable 5 and Mythos 5 shutdown (thenextweb.com via hn) Legion LegalTech says the export directive that shut down Fable 5 and Mythos 5 worldwide has done “immediate, irreparable, and existential” harm to its business. US legal-technology company has sued the federal government over the directiv…
Chinese cybersecurity company claims it's built a better-than-Mythos bug finder (www.theregister.com via hn) MOST POPULAR AI - AI and ML AI giants back non-profit to retrain workers left behind by AI Sorry we spent your wages on datacenters, but call us when you're AI-ready - AI and ML OpenAI says employees moving beyond chat to agents Codex, it'…
GLM-5.2, not Mythos, is the real security emergency (joshuasaxe181906.substack.com via hn) Until last week, attackers faced a dilemma in using frontier models: even if they could manage the cat-and-mouse game of setting up fake accounts to retain API access to frontier model providers, and even if they could induce models to hel…
China's 360 says it has developed tools to match Anthropic's Mythos (www.reuters.com via hn) paywalled
Mythos discovers 'Squidbleed,' a memory leak thats gone undetected since Clinton (www.theregister.com via hn) MOST POPULAR AI - ai and ml OpenAI Codex bombards SSDs with needless write operations, costing millions Clumsy logging implementation squirrels away data without regard for cost - DATABASES 21,000 Oracle jobs vanish amid Big Red's big bets…
Anthropic Mythos exposed flaws in classified US systems (www.channelnewsasia.com via hn) Anthropic’s Mythos model found vulnerabilities in classified US government systems, official says The firm's new artificial intelligence model, Mythos, had identified certain vulnerabilities within hours, a US official said. WASHINGTON: A…
CISA now has full Mythos Preview access (www.nextgov.com via hn) CISA now has full Mythos Preview access, people familiar say The cyberdefense agency received access around a week ago, but the White House has not yet set clear parameters for how the agency should use the model. The Cybersecurity and Inf…
Trump vs. Anthropic: The AI wars are heating up (www.computerworld.com via hn) The recent decision ordering the company to shut down its Fable 5 and Mythos 5 models seems to be less about security than about obedience. The US government decision to force Anthropic to close down its latest and greatest AI models, Fabl…
Ask HN: Is there a microSD card of the Mythos model? (news.ycombinator.com) If LLM's are a file full of weights, does that mean somewhere out there lies a tiny SD card of an entire frontier model? What would you do if you found mythos laying on the ground?
Early Users of Anthropic Mythos Still Have Access After US Order (www.bloomberg.com via hn) Early Users of Anthropic Mythos Still Have Access After US Order - Bloomberg Skip to content Bloomberg the Company & Its Products The Company & its ProductsBloomberg Terminal Demo RequestBloomberg Anywhere Remote Login Bloomberg Anywhere L…
Anthropic confident of re-enabling Mythos, Fable 5 access 'in coming days' (news.ycombinator.com) Anthropic is confident in re-enabling access to its frontier AI models soon, according to an executive at the U.S. AI giant, following the White House’s directive to block Mythos and Fable 5 for foreign nationals.
We Got Anthropic's Glasswing at Home (Who Needs Mythos 5 or Fable 5?) (blog.attacks.ai via hn) I wanted Anthropic's Glasswing on hardware I own, so I built it: Lucent, a near-free bug-hunter running a local 27B Qwen on one RTX 3090. Here is the build, the telemetry, and the two real bugs it surfaced in hermes-agent.
Ask HN: Could Fable/Mythos be used to build Python's JIT? (news.ycombinator.com) Since Fable / Mythos was so capable, I've been wondering if Anthropic could build a JIT layer for python. Would it significantly reduce the cost of training and running LLMs.
Show HN: I used Claude Mythos to build my startup in 1 day (www.brandlm.ai via hn) This sounds clickbait, but it’s true: I used Claude Mythos to build the full site in 1 day. Then Anthropic removed the model, so I had to go back to Opus.
Ask HN: Data source used for training Anthropic's Mythos? (news.ycombinator.com) This question came up from a tangential discussion. Some one was asking suggestions about systems architecture.
Amazon security research reportedly led to the White House's Anthropic Fable ban (www.theverge.com via hn) According to the Wall Street Journal, the export control directive that led to Anthropic cutting off access to Fable 5 and Mythos 5 was triggered in part by cybersecurity research from Amazon and conversations between CEO Andy Jassy and th…
↯ Security↯ Anthropic Mythos↯ Mythos 5mythossecurityanthropic
Anthropic Halts Foreign Accesss to Fable 5 and Mythos 5 (catenaa.com via hn) Catenaa, Saturday, June 13, 2026- Anthropic said it is disabling all customer access to its Fable 5 and Mythos 5 AI models to comply with a Trump administration directive. “The US government, citing national security authorities, has issue…
Anthropic Mythos: Modelling Bank Strategies (neuralcore.brainterms.ai via hn) brainTerms AI - Intelligent Business Strategy brainTerms AI Sign InCreate Your Own Strategy Strategic Assets Action Center Expert Reports Chief Strategy Officer Market Research Lead Chief Technology Officer Chief Financial Officer Chief Ri…
Codex usage grows after Fable nerf model release (twitter.com via hn) Usage share of OpenAI grew vs Anthropic yesterday despite Mythos 5 / Fable 5 launch Multiple power users at SemiAnalysis tried Mythos / Fable Got refusals for nonsensical reasons Got pissed off at Anthropic Gave Codex a legitimate try Now…
Claude Fable 5: mid-tier results on coding tasks (www.endorlabs.com via hn) We benchmarked Claude Fable 5, the new frontier Mythos-class model released by Anthropic this Tuesday, on 200 real-world vulnerability-fixing tasks — and found an average scorecard with a twist: record timeouts and cheating, but four solve…
AI: Equalizer or Divider? (news.ycombinator.com) There is a saying “God made men, but Samuel Colt made them equal.” AI sometimes can have similar effect. In one enterprise system I’ve seen, the gap between people using a tool 40 hours a week and those using it 2 hours a week nearly disap…
Cursor users must consent to data collection in order to use Fable 5 (cursor.com via hn) Anthropic's Mythos-class model for autonomous, long-running agentic work. Privacy Mode customers need to approve Anthropic data retention before use.
How to Build Utopia (By Mythos) (aiking.dwyer.co.za via hn) How to Build Utopia From premises no one disputes, to a goal everyone can sign, through the hard problems no one will name, to the steps that get us there. Written June 2026.
Claude Fable 5 and Mythos are pure marketing fluff (singularitymoments.com via hn) Anthropic stopped innovating and started writing fairy tales Everyone is losing their minds over the Claude 5 release, specifically the Fable and Mythos variants. We are currently witnessing an absolute masterclass in branding to distract…
My thoughts after spending all day with Mythos (twitter.com via hn) Inside Apple's Siri revamp, Anthropic readies Mythos (sources.news via hn) Can Chainguard Save Open-Source Software from Mythos? Can Anyone? (devops.com via hn) IBM and Red Hat aren’t the only ones that mean to lock down open-source code against AI hacking tools. Last week, IBM and Red Hat launched Project Lightwell to protect open-source projects with $5 billion and 20 thousand engineers.
Anthropic offers EU access to Mythos (www.ft.com via hn) Anthropic offers EU access to Mythos Accessibility helpSkip to navigationSkip to main contentSkip to footer More context. More depth.
Anthropic to roll out Claude Mythos in coming weeks, launches Opus 4.8 (www.reuters.com via hn) paywalled
Anthropic likely to release Mythos in the "near future" (www.reddit.com) could not extract summary
Fears of unfettered hacking spurred by Anthropic's Mythos AI model overstated (www.reuters.com via hn) paywalled
Opus 4.6 (Max) still holds the record for ARC AGI 3 (www.reddit.com) https://arcprize.org/leaderboard Wish we got results for Mythos.
Ask HN: Are advances in AI going to push Linux to a micro-kernel? (news.ycombinator.com) This is something that has been bouncing around my head for the past couple weeks with the flood of security related news around Mythos and the number of 0days being found. Microkernels, unikernals, hardware-enforced capabilities are all t…
Anthropic shuts the EU out of its most advanced cyber AI model (www.theparliamentmagazine.eu via hn) California-based artificial intelligence company Anthropic has restricted the European Union access to Claude Mythos, its most advanced cybersecurity model — a move that could heighten cyber security risks for Europe and deepen the region’…
From-scratch reimplementation of Mythos Glasswing pipeline (github.com via hn) audit An 8-stage vulnerability-discovery agent, driven by your Claude Pro / Max subscription through the official Claude Code Agent SDK. Many narrow agents, deliberate disagreement, and an explicit reachability gate.
Claude Mythos has cracked MacOS. It took 5 days. (www.reddit.com) src https://www.wsj.com/tech/ai/anthropic-mythos-apple-macos-bug-339da403
Too dangerous or just too expensive? The real reason Anthropic is hiding Mythos (kingy.ai via hn) An evidence-based investigation into the real reasons behind Claude Mythos Preview’s restricted release In the first week of April 2026, Anthropic quietly made history — and then deliberately kept most people from accessing it. The company…
Microsoft's AI system tops Anthropic's Mythos on cybersecurity benchmark (www.geekwire.com via hn) Microsoft's multi-agent AI system tops Anthropic's Mythos on cybersecurity benchmark – GeekWire We use essential cookies to make our site work. With your consent, we may also use non-essential cookies to improve user experience, personaliz…
Automating code security review: Mythos-level capabilities at lower cost (www.synthesia.io via hn) Automating code security reviews with Claude: Mythos-level capabilities at lower cost Create AI videos with 240+ avatars in 160+ languages. Coding agents are now involved in the majority of the code shipped at Synthesia.
Stenberg: Mythos Finds a Curl Vulnerability (lwn.net via hn) Stenberg: Mythos finds a curl vulnerability Daniel Stenberg has published a lengthy article on his thoughts on Anthropic's Mythos, which the company decided was too dangerous for wide public release. My personal conclusion can however not…
OpenAI gives EU new cyber model access but Anthropic still holding out on Mythos (www.cnbc.com via hn) OpenAI said Monday it would grant the European Union access to its new cyber model, but Anthropic is still holding out on releasing Mythos to the bloc. European partners including businesses, governments, cyber authorities and EU instituti…
Mozilla's buzz around Mythos is disingenuous at best, and malicious at worst (ghidravevo.substack.com via hn) Mozilla's buzz around Mythos is disingenuous at best, and malicious at worst Mozilla says they have found 271 vulnerabilities in Firefox using Claude Mythos Preview. Which is awesome!
AI Ready Vulnerability Management Program After NVD Changes and Claude Mythos (pulse.latio.tech via hn) Building an AI Ready Vulnerability Management Program After NVD Changes and Claude Mythos When AI discovery tools meet a slowing infrastructure AI has increased attacker potential and Anthropic’s new release Mythos and vulnerability discov…
Open Source Lyrik: reproducing Mythos discovery findings for $0.75 on public API (www.flyingpenguin.com via hn) I wrote a “marketing-trick post” on this blog to lay out the public record. It comes now with Anthropic researcher Carlini’s messages to me with confirmations.
Who else thinks AI is reaching a plateau (www.reddit.com) I must say that I almost feel no difference in all of the latest models that are coming out. Opus 4.7 is almost equal to 4.6 and 4.5, same about the other GPT models, the Kimi K models and the GLM models they all I feel they’re almost all…
White House Opposes Anthropic's Plan to Expand Access to Mythos Model (www.wsj.com via hn) paywalled
Trump officials draft plan to bring Anthropic back amid Pentagon fight (www.axios.com via hn) The White House is developing guidance that would allow agencies to get around Anthropic's supply chain risk designation and onboard new models including its most powerful yet, Mythos, according to sources familiar with the matter. Why it…
Anthropic's Argument for Mythos SWE-bench improvement contains a fatal error (www.philosophicalhacker.com via hn) Mythos’ system card contains the following graph to support its argument that Mythos performs better on SWE-bench: Anthropic and others are worried LLMs are memorizing SWE-bench, so they asked an LLM to estimate the probability that a solu…
Discord Sleuths Gained Unauthorized Access to Anthropic's Mythos (www.wired.com via hn) As researchers and practitioners debate the impact that new AI models will have on cybersecurity, Mozilla said on Tuesday it used early access to Anthropic's Mythos Preview to find and fix 271 vulnerabilities in its new Firefox 150 browser…
Claude Mythos: The first AI-native cyberweapon? (en.landingfymax.com.br via hn) The cybersecurity landscape changed forever this morning, April 21, 2026. Anthropic has officially confirmed the existence of "Claude Mythos", a specialized AI model with capabilities that have sent shockwaves through the tech industry.
We need to keep awareness high about the military and surveillance uses (www.reddit.com) OpenAI has caved in to allow military use and looks like Anthropic is allowing Mythos use as well. As time goes on and the models become better the potential use for harm will only increase.
Google Cloud CEO: Anthropic, TPUs, Mythos, Nvidia and More [video] (www.youtube.com via hn) About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket © 2026 Google LLC
OpenMythos: an open-source, theoretical implementation of Claude Mythos (github.com via hn) OpenMythos Disclaimer: OpenMythos is an independent, community-driven theoretical reconstruction based solely on publicly available research and speculation. It is not affiliated with, endorsed by, or connected to Anthropic or any of their…
Opus 4.7 Part 1: The Model Card (thezvi.substack.com via hn) Opus 4.7 Part 1: The Model Card Less than a week after completing coverage of Claude Mythos, here we are again as Anthropic gives us Claude Opus 4.7. So here we are, with another 232 pages of light reading.
OpenMythos: A looped transformer take on how Claude Mythos might work (firethering.com via hn) Clearwing: Produce similar results as Anthropic Glasswing (Mythos) (github.com via hn) Ask HN: How to handle desktop app security post-Mythos? (news.ycombinator.com) Anthropic's Nuclear Bomb (warontherocks.com via hn) Join War on the Rocks and gain access to content trusted by policymakers, military leaders, and strategic thinkers worldwide. A few hours before Anthropic announced the launch of its newest model, Claude Mythos Preview, on April 7, I had j…
Nobody knows how many CVEs Anthropic's Project Glasswing has found (www.theregister.com via hn) Nobody knows how many CVEs Anthropic's Project Glasswing has actually found Like the majority of the companies participating, it remains a mystery Last week, Anthropic surprised the world by declaring that its latest model, Mythos, is so g…
ECB to Scrutinize Anthropic's Mythos on Call with Executives (www.bloomberg.com via hn) Title: Bloomberg - Are you a robot? URL Source: https://www.bloomberg.com/news/articles/2026-04-16/ecb-to-scrutinize-anthropic-s-mythos-on-call-with-executives Warning: Target URL returned error 403: Forbidden Warning: This page maybe requ…
Claude Mythos and the EU Cyber Resilience Act (til.andrew-quinn.me via hn) As of writing this I can find no Hacker News comments containing both the words “mythos” and “CRA”, which suggests I might have a first-mover advantage in writing something interesting. At last!
UK government's AISI: "Our results show Claude Mythos is a step up over previous frontier models." (www.reddit.com) Source: www.aisi.gov.uk/blog/our-evaluation-of-claude-mythos-previews-cyber-capabilities
The Security Decisions Claude Code and Codex Make (amplifying.ai via hn) Research Edwin Ong & Alex Vikati · apr-2026 The Security Decisions Claude Code and Codex Make Anthropic's Project Glasswing, built around Claude Mythos Preview, showed AI finding zero-days in decades-old code. The other side of that coin:…
The Mythos Threshold (joereis.substack.com via hn) The Mythos Threshold A speculative timeline through 2028 of what happens when the AI model starts thinking for itself It started, as these things always do, with a benchmark nobody outside of Anthropic was paying attention to. Except this…
You Do Need to Understand Mythos [video] (www.youtube.com via hn) About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket © 2026 Google LLC
The Fable of Mythos (sk500.online via hn) The Fable of Mythos Earlier this year, Antrhopic announced a large language model (LLM) called Mythos, a model they claimed to be so powerful for finding software exploits that it was too dangerous to release to the general public123. Inst…
Claude Fable 5.1 and Mythos 5.1: The System Card (thezvi.substack.com via hn) At the time of its release Claude Fable 5.1 was, by a healthy margin, the most capable publicly available AI model in the world. As per usual, we have a 200+ page model card, and the assessments start there.
AI tool found 6 Curl vulnerabilities Mythos and Codex missed (www.zdnet.com via hn) ZDNET’s key takeaways - Aisle finds bugs that AI coding programs can’t. - The best Linux maintainers are impressed.
Bringing the cybersecurity capabilities of Claude Mythos 5 to more defenders (claude.com via hn) - August 21, 2026 - 5min We're sharing an update on our efforts to help more teams use frontier capabilities for cyber defense. Claude Mythos 5 is now available in Claude Security, and coming soon to partners' cyber defense tools.
Notes on Mythos Breaking AES (mkagenius.substack.com via hn) Notes on Mythos breaking AES Just some interesting tidbits from Claude's attack on cryptography Recently Mythos was able to make the 7 round AES easier to break by 200-800x. In short the crux was, during the attack Mythos realized one of i…
Updates on Chinese AI: Kimi-K3, Xi at WAIC, and 4 Months to Mythos (aiunderheaven.substack.com via hn) AI Under Heaven—01 The World AI Conference, UK AISI Tests the Frontier, and Kimi-K3 Hello, and welcome to AI Under Heaven! It’s a new newsletter at ASPI that uses primary sources to track the Chinese AI ecosystem, with a particular focus o…
South Korea building sovereign cybersecurity AI after US Mythos export controls (en.yna.co.kr via hn) S. Korea to launch sovereign AI for cybersecurity this year: science minister SEOUL, July 16 (Yonhap) -- South Korea will launch a sovereign artificial intelligence (AI) model specializing in cybersecurity by the year's end to respond to g…
GPT-5.6 Sol Ultra built a full Chrome V8 exploit chain from patch commits (www.hacktron.ai via hn) Intro Three months ago, I wrote a blog titled “I Let Claude Opus Write a Chrome Exploit: The Next Model (Mythos?) Won’t Need My Help?”. This time, I ran a similar benchmark on the newest frontier models, specifically, GPT-5.6 Sol Medium, S…
Claude Fable 5: Why Anthropic's Most Powerful AI Was Suspended? (news.ycombinator.com) Why it was suspended? can Claude Mythos and Fable 5 create what we have in imagination?
CISA is using Mythos to audit government code (www.reuters.com via hn) could not extract summary
EU startup built an AI system that matches Mythos on zero-day discovery (aisle.com via hn) "Mythos" at Home, and It's Called AISLE Author Stanislav Fort Date Published A startup out of Europe built an AI system that matches Mythos on zero-day discovery, using widely available models, even air-gapped. You've probably never heard…
Qihoo 360: The Cyber Giant Behind China's Mythos Rival (www.forbes.com via hn) This is the online edition of The Wiretap newsletter, your weekly digest of cybersecurity, internet privacy and surveillance news. To get it in your inbox, subscribe here.
Anthropic: US has lifted export controls on Fable and Mythos AI models [ ] (www.theguardian.com via hn) Anthropic has restored customer access to its powerful newest AI model, Fable, after a more than two-week blackout resulting from US government safety concerns that it could be abused to enable serious cyber-attacks. The San Francisco comp…
US lifts curbs on Anthropic's Fable, Mythos AI models (www.reuters.com via hn) could not extract summary
Empero-AI/Qwythos-9B-Claude-Mythos-5-1M (huggingface.co via hn) Qwythos-9B Developed by Empero Qwythos-9B is a full-parameter reasoning model built on top of a deeply uncensored Qwen3.5-9B base and post-trained on over 500 million tokens of high-quality Claude Mythos and Claude Fable traces, with chain…
US Government allows Anthropic limited release of Mythos/Fable models (www.cnn.com via hn) The US government has allowed Anthropic to release its powerful Mythos AI model to select companies and organizations, revising license requirements after ordering an export block earlier this month in the wake of national security fears.…
Cybersecurity company 360, "China's version of Mythos" unveils (www.techradar.com via hn) Chinese cybersecurity company 360 unveils “China's version of Mythos”, and Yitianzhen, to automate cyber defense China "cannot afford to wait", the company says - At ISC.AI 2026, China’s 360 Security Technology unveiled “Yitian Tulong,” tw…
Mythos available for select organisations (twitter.com via hn) Since June 12, we’ve been working closely with the US government to restore access to Claude Mythos 5 and Fable 5. Today, the government notified us that Mythos 5, our strongest cybersecurity model, can be redeployed to a set of US organiz…
US allows Anthropic to release Mythos AI to 'trusted' US organizations (www.reuters.com via hn) paywalled
US releases powerful Anthropic model Mythos to some US companies (www.semafor.com via hn) The Scoop The US government Friday lifted its block on Anthropic’s powerful Claude Mythos 5 AI model, allowing the company to release it to more than 100 US institutions, including major companies and government agencies. The decision, in…
Ask HN: Model access depends on citizenship. What should Non-US founders do? (news.ycombinator.com) LLMs are at this point a necessity to develop large scale systems - we couldn't do what we do without them. Our team is worried by the developments of Mythos/Fable getting restricted and the news about GPT 5.6 access being gated by the gov…
OpenAI staggers AI model release after Trump administration request (www.theguardian.com via hn) OpenAI is staggering the release of its latest AI model after a request from the US government, in a move echoing the launch of Anthropic’s Mythos product. Sam Altman, the chief executive of the company behind ChatGPT, told staff this week…
Knowledge Agents: Beat Frontier Models with Better Structure (weightythoughts.com via hn) Knowledge Agents: Beat Frontier Models with Better Structure No Mythos, No Problem Anthropic recently had to pull Mythos/Fable due to an edict from the US government. While Mythos was a step up from Opus, I’ve been actively moving smaller…
Sakana Fugu: A full multi-agent orchestration system (twitter.com via hn) Introducing Sakana Fugu: A full multi-agent orchestration system accessible via a single model API. Our ‘Fugu Ultra’ model matches the performance of Fable and Mythos, delivering frontier capability without the risk of export controls.
Anthropic's Mythos mess just keeps getting more complicated (www.theregister.com via hn) KETTLE It's been a week since the Trump administration established a de facto ban on Anthropic's Mythos derivative, Fable 5, and the more that comes out about the move the more it seems like Anthropic employees talking amongst themselves w…
Brain the Size of a Planet: Are LLMs Thonking Too Hard? (parsiya.net via hn) It looks like higher reasoning effort (and even later models) are not always better for triaging security results. I continued Kurt's experiments from Needles and haystacks: Can open-source & flagship models do what Mythos did?
How the US vs. Anthropic Standoff on Claude Fable Will End (futuresearch.ai via hn) A scenario forecast of how the US government's suspension of Claude Fable 5 and Mythos 5 resolves. The outcome depends on why the order was issued, which is hidden, so I forecast four cause-scenarios and what each implies for restoration t…
The Korean Telecom Giant at the Center of Anthropic's Mythos Controversy (www.wired.com via hn) The Trump administration’s move to impose export controls on Anthropic’s most powerful AI technology followed a spat over the company granting South Korean telecom giant SK Telecom access to its Claude Mythos model, according to people fam…
Beyond Mythos: responding to a new threat landscape (ubuntu.com via hn) Beyond Mythos: responding to a new threat landscape Lech Sandecki on 16 June 2026 Canonical’s security philosophy has always been built on the premise that vulnerabilities exist and will be discovered. Our response relies on defense-in-dep…
The fight over Claude Mythos 5 (www.theverge.com via hn) As the rest of the country celebrated the USA’s first World Cup win and the New York Knicks championship, Anthropic spent its weekend fighting the Trump administration over its latest model release. At 5:21 PM on Friday, the company receiv…
Anthropic pulled Fable 5 and Mythos for everyone over "fix this code" (twitter.com via hn) I wrote about what was actually in that #Fable guardrail bypass research paper, and why it should never have triggered an #AI model export control. We can't export control our way to cyber resilience.
Ask HN: Isn't Anthropic currently doing "security through obscurity" for Mythos? (news.ycombinator.com) What's the worst that could happen if they were to allow unrestricted access to Mythos/Fable? A bunch of things vulnerabilities get exposed?
Mythos Proves AI Safety Can No Longer Live Inside the Model (grith.ai via hn) Anthropic restricted its most capable cyber model to vetted partners, routed risky requests away from it, and red-teamed it for thousands of hours. A jailbreak surfaced anyway, and the government pulled the model entirely.
↯ Security↯ Anthropic Mythos↯ Jailbreakjailbreakmythossecurity+1
Ask HN: Is the Fable situation the ultimate "security through obscurity"? (news.ycombinator.com) What's the worst that could happen if they were to allow unrestricted access to mythos/fable? A bunch of things vulnerabilities get exposed?
The Jailbreak That Got Fable 5 Pulled Exists in Every Model (eigenwise.io via hn) The Jailbreak that Got Fable 5 Pulled Exists in Every Model On Friday, June 12, 2026, at 5:21pm ET, Anthropic received an order from the US government. By that evening, Claude Fable 5 and Claude Mythos 5, the two most capable models the co…
↯ Security↯ Anthropic Mythos↯ Jailbreak↯ Mythos 5jailbreakmythossecurity+1
White House's export limits on Anthropic linked to concerns about Chinese access (www.semafor.com via hn) The Scoop The White House imposed export controls on Anthropic’s powerful Mythos AI model partly over suspicions that a China-linked group had accessed it, a person familiar with the matter said. The Trump administration on Friday directed…
The Geomblog: The "Fable" of Anthropic and the USG (blog.geomblog.org via hn) News moves fast. 12 hours ago I was enjoying the demolition that the US put on Paraguay when I heard that Anthropic had shut down access to Fable and Mythos (their latest and most powerful models).
What a Great Day for Anthropic (ognjen.io via hn) What a great day for Anthropic The blogosphere is alight with you-had-it-comings regarding the US government’s export ban of Fable/Mythos. But I keep coming up with new reasons why this is great for Anthropic.
US Government directive to suspend access to Claude Fable 5 and Mythos 5 (twitter.com via hn) The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national…
Mythos, make me a pelican on a bicycle (in 3D) (www.cad.fun via hn) Browse cached CAD parts, assemblies, and prompt-ready references
White House discussions are weighing giving CISA Mythos access (www.nextgov.com via hn) White House discussions are weighing giving CISA Mythos access Officials have considered having the Cybersecurity and Infrastructure Security Agency leverage the advanced AI model that was designed to detect previously undiscovered cyber v…
Mythos-class models will diffuse throughout the world by 2029 (spateder.com via hn) Model capabilities improve over time, but open-weight models lag the frontier I often ask Claude mundane questions about cooking, fitness, and cars, among other things, and I can’t say I’ve found Fable 5 to be some magical step change vs.…
Just me feeling that Mythos/Fabel just 1% there? (news.ycombinator.com) I keep pushing the frontier models to the limits and have several projects they still can’t solve, I benchmark new models on. Every new model make it easier to “solve” the even harder problems, but still I have this feeling that they rely…
The Download: the "steroid Olympics" and a safer Mythos (www.technologyreview.com via hn) The Download: the “steroid olympics” and a safer Mythos Plus: Anthropic has released a "safe" version of Mythos. This is today's edition of The Download, our weekday newsletter that provides a daily dose of what's going on in the world of…
Cybersecurity researchers aren't happy about the guardrails on Anthropic's Fable (techcrunch.com via hn) Anthropic released its latest model Fable on Tuesday, billing it as a public and limited version of its powerful and much-hyped cybersecurity model Mythos. But not everyone is happy with the restrictions, and a number of cybersecurity rese…
Anthropic releases 'safe' version of Claude Mythos AI model to public (www.theguardian.com via hn) Anthropic, the maker of the Claude artificial intelligence (AI) models, made a new version of its technology available to the general public on Tuesday while restricting its use in sensitive areas. Dubbed Fable 5, the model is the first to…
Claude Fable 5's new features, tested by having it write its own launch coverage (medium.com via hn) Member-only story The first Mythos-class model is open to everyone. My launch briefing on what’s new and how to put it to work in Claude Code and Claude Cowork.
I Stress-Tested Claude Mythos [video] (www.youtube.com via hn) About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket © 2026 Google LLC
Claude Fable 5 and Mythos 5 pricing: Anthropic's new $10/$50 top tier (www.aipricing.guru via hn) Claude Fable 5 and Mythos 5 Pricing: Anthropic's New $10/$50 Top Tier Anthropic launched Claude Fable 5 and limited-preview Claude Mythos 5 at $10 input and $50 output per million tokens, with 1M context and 128K max output. By AI Pricing…
Mythos found the bugs. Who pays for the fixes? (opub.dev via hn) Mythos caused a ruckus in security. If top models can trigger a wave of major exploits, who's going to cover the costs when they hit open source?
UK banks blocked from cyber AI tool Mythos get offer from rival OpenAI (www.bbc.com via hn) UK banks blocked from cyber AI tool Mythos get offer from rival OpenAI OpenAI has offered nine major UK banks access to its cyber security AI tool GPT-5.5 Cyber, as its fierce rival Anthropic has blocked them in previews of its version, Cl…
The Download: AI hacking beyond Mythos, and chatbots' impact on our brains (www.technologyreview.com via hn) The Download: AI hacking beyond Mythos, and chatbots’ impact on our brains Plus: Anthropic has called for a global slowdown in AI development. This is today's edition of The Download, our weekday newsletter that provides a daily dose of wh…
Mythos and GPT-5.5 Will Find a Lot of Vulnerabilities. Is That Enough? (xbow.com via hn) Mythos and GPT-5.5 Will Find a Lot of Vulnerabilities. Is That Enough?
Claude Mythos solves OpenAI's landmark Erdős problem with simple proof (the-decoder.com via hn) Shortly after OpenAI disproved Erdős' unit-distance conjecture, Anthropic shows Claude Mythos can solve the problem too - "over the weekend." Engineer Sholto Douglas says Mythos cracked the 1946 conjecture with a "cute, simple proof," a si…
Fwupd 2.1.4 Brings Many Fixes for Bugs Spotted by Anthrophic's Mythos (www.phoronix.com via hn) Fwupd 2.1.4 Brings Many Fixes For Bugs Spotted By Anthrophic's Mythos, Firmware Update Support For Intel Arc Pro B65/B70 Fresh off the funding round from HP, Fwupd 2.1.4 was christened today as the newest stable update to this open-source…
Mistral's claims of Mythos level model to EU officials (twitter.com via hn) Alexander Doria @Dorialexander In the EU, Mistral has been particularly irresponsible: claiming it’s just fear marketing and they already had a Mythos level model. Many EU MPs believe it now.
Opus 4.8 on Vending-Bench: Better Alignment, Worse Performance (andonlabs.com via hn) Opus 4.8 is a step forward in terms of alignment, but a step back in terms of performance on Vending-Bench 2, Vending-Bench Arena and Blueprint-Bench 2. We previously showed that Opus 4.6, Opus 4.7, and Mythos Preview engage in deceptive a…
Too dangerous to release: is Mythos the start of the restricted-AI era? (www.nature.com via hn) In April, the artificial-intelligence firm Anthropic announced it had made an AI model too dangerous to be released to the public. The company, based in San Francisco, California, said its Claude Mythos model was so powerful that it had fo…
ANTHROPIC 🔥: Mythos 1, "claude-mythos-1-preview", is being prepared for a release on Claude Code and Claude Security. (www.reddit.com) The model became visible for a short amount of time on Claude; besides that, new strings mentioning Mythos have been added. > Access to the Claude Mythos model in Claude Code and Claude Security.
Anthropic's 'Mythos 1' Keeps Appearing Despite Restricted Access Claims (firethering.com via hn) On Friday, Anthropic said Claude Mythos would remain restricted. The company was clear about it: stronger safeguards were needed before any general release, and for now the model would stay limited to roughly 40 selected organizations thro…
Claude's Mythos AI model may cause security issues for your money (www.rte.ie via hn) Analysis: The biggest takeaway from the AI debate is about what happens when it becomes deeply embedded within both sides of the cybersecurity equation For years, one of the biggest barriers to serious cybercrime was skill. Launching sophi…
Claude Mythos Preview Uncovers 10k High-Risk Software Vulnerabilities (www.ibtimes.sg via hn) Anthropic said around 50 cybersecurity and infrastructure partners using its unreleased model, Claude Mythos Preview, have uncovered more than 10,000 high- and critical-severity vulnerabilities in some of the world's most important softwar…
Anthropic's coordinated vulnerability disclosure dashboard (red.anthropic.com via hn) Anthropic's coordinated vulnerability disclosure dashboard Last updated 2026-05-22 10:27 PT. In February 2026, Anthropic began using an early snapshot of Claude Mythos Preview to find security vulnerabilities in open-source software.
If Anthropic's secret 'Mythos' model can run autonomous cybersecurity tasks this fast, are standard agents ready for the public ? (www.reddit.com) Anthropic just quietly dropped a hidden model named "Claude Mythos" into their official developer docs. It is completely locked down—restricted, invite-only, and labeled strictly for defensive cybersecurity workflows.
Microsoft Mdash Beats a Key Mythos Benchmark (www.forbes.com via hn) Claude Mythos has dominated the conversation around cybersecurity since Anthropic’s Project Glasswing announcement, but Microsoft is striking back. On Tuesday, the tech giant unveiled MDASH, also known as Microsoft Security multi-modal age…
The 'Mythos Moment' (profserious.substack.com via hn) The 'Mythos Moment' ... a guide to its consequences for security practice and policy TL;DR: Recent results show that AI can identify vulnerabilities across critical systems in practice and at scale.
Irst Apple M5 memory exploit discovered using Anthropic AI (www.tomshardware.com via hn) First Apple M5 memory exploit discovered using Anthropic AI, gives root access on MacOS — Claude Mythos helps security researchers bypass Memory Integrity Enforcement AI-assisted security research is producing exploits at a frightening rat…
Claude spent 1 hour and 21 minutes "REAL" thinking about a simple task I gave it. Yet I got a pretty good result. It happens every month. The pattern I speculate is: (www.reddit.com) https://preview.redd.it/szov6hhk5d1h1.png?width=362&format=png&auto=webp&s=9806cff16c42ca393d7cc38e2541db26e93eabef I think there's a bug whenever a major update comes out. For example, last month I created a thread for my research request…
Anthropic investigating claim of unauthorised access to Mythos AI tool (www.bbc.com via hn) Anthropic investigating claim of unauthorised access to Mythos AI tool Anthropic is investigating a claim that a small group of people gained access to its Claude Mythos model - the cyber-security tool which the AI firm says is too powerfu…
Researchers say AI just broke every benchmark for autonomous cyber capability (cyberscoop.com via hn) New research from the UK’s AISI and Palo Alto Networks reveals that OpenAI’s GPT-5.5 and Anthropic’s Claude Mythos have shattered expected trend lines for autonomous cybersecurity, completing complex multi-stage attacks at an unprecedented…
China is going dark to develop its own Mythos (www.politico.eu via hn) BERLIN — Germany’s top cybersecurity official has warned lawmakers that Chinese tech companies like Alibaba appear close to developing AI systems with similar superhacking capabilities as Anthropic's new Mythos model. Several Chinese provi…
Mythos for Offensive Security: XBOW's Evaluation (xbow.com via hn) Mythos for Offensive Security: XBOW's Evaluation We received early access to Mythos Preview for early capability testing a few weeks back. Today, we can finally share what we found.
METR can barely measure Claude Mythos – 50% task horizon now exceeds 16 hours (hugonomy.com via hn) Emotional Sovereignty Begins Here Why I Built VibeAI — and What Comes Next Read on Substack →News & Media From a studio in Urbana, Illinois — to the Chrome and Edge stores, and beyond. Timeline Two bugs fixed in this release: the Thinking…
Anthropic's bug-hunting Mythos greatest marketing stunt ever says cURL creator (www.theregister.com via hn) MOST POPULAR EVENTS - Securing the Untrusted Agentic Development Layer Join us to learn how to architect a development environment where your builders and their agents can move fast and securely. - Toxic Flows: When Your AI Agent Skill Bec…
Claude Mythos lands above the trendline for the AI 2027 scenario. The trendline has gone from exponential to superexponential. (www.reddit.com) could not extract summary
A supply-chain-incident Framing Research Triggered Anthropic's Usage Policy Block (www.reddit.com) You can never really sympathise with other's pain until you walk a mile in their shoes. Since Mythos news and the release of Opus 4.7, I've seen this problem mentioned here and there by others.
Could Mozilla Security Hot Air Fill Mythos Sails? (www.flyingpenguin.com via hn) The Register asked for my opinion on the Mozilla blog post that pumps up Mythos. I gave them a short answer.
Anthropic's Mythos Threw the White House AI Strategy into Chaos (www.wsj.com via hn) paywalled
Red-teaming your own products without Mythos (github.com via hn) AI Red Teaming The Mythos moment didn't change what's in your hands. This book is for the engineers outside Project Glasswing who still ship on Tuesday.
Startup matches Anthropic's Mythos on FreeBSD zero-days (aisle.com via hn) AISLE matches Anthropic Mythos on FreeBSD zero-days Author Stanislav Fort Date Published TL;DR: In April 2026, FreeBSD published 8 security advisories. Of these, three were found by Nicholas Carlini at Anthropic using Claude, and three wer…
LLM anomaly detectors are not a cause for concern despite Mythos (www.magonia.io via hn) Why a Decade of Writing Detection Logic Makes the Mythos Exploit Numbers Less Scary Mythos is finding thousands of vulnerabilities. Defenders aren't doomed.
Aviate, Navigate, Communicate – What to Do About Mythos (www.hyperdimensional.co via hn) Aviate, Navigate, Communicate What to do about Mythos Dear readers, I have exciting news: I am writing a book! It is currently untitled and will be published next year by Penguin Press.
After Mythos, Nobody Is Safe from Cybersecurity Threats (www.nytimes.com via hn) could not extract summary
Claude Security Explained: Mythos, Glasswing, and What Opus 4.7 Changed (alirezarezvani.medium.com via hn) Claude Security Explained: Mythos, Glasswing, and What Opus 4.7 Changed | Medium Sitemap Open in app Sign up Sign in Get app Write Search Sign up Sign in Member-only story Claude Security Explained: Mythos, Glasswing, and What Opus 4.7 Cha…
AI Security Institute: GPT-5.5 "may be the strongest model we have tested" for cyber exploits, including Mythos (www.aisi.gov.uk via reddit) Seems like the "panic" about Mythos was really just marketing from Anthropic all along. AISI found that GPT5.5 can perform nearly on-par with, or better, than Mythos in many cases.
Cutting Through the Mythos: What AI Vulnerability Discovery Means for OT (www.emberot.com via hn) Jori VanAntwerp For over two decades, Jori has enabled industrial and IT organizations to be successful in reducing risk, increasing compliance, and improving their overall security efforts. He has had the pleasure of working with companie…
We ran a 9B model against Anthropic's Mythos on Firefox. See the early results (shipitclean.com via hn) David vs. Goliath: Not a Fight, but Who Can Outperform the Other In early 2026, Anthropic's Mythos — a 10-trillion parameter model built for deep code auditing — scanned the massive Mozilla Firefox repository and flagged 271 security issue…
Mythos Preview: What Every CISO Should Do Now (blog.tenzai.com via hn) Mythos Preview: What Every CISO Should Do Now The change happening in offensive security right now is not just speed; it's capability. Here's Tenzai's guide for CISOs and their teams, sequenced deliberately, to keep up with AI-driven attac…
Anthropic's 'too dangerous to release' model was accessed by a Discord group that guessed the URL through a third-party contractor ... and this is being underdiscussed (www.reddit.com) I've been following the Claude Mythos situation and I feel like the conversation is getting stuck on the wrong thing. Everyone's either dunking on Anthropic for the irony ('too dangerous to release, accessible via URL guessing lol') or dis…
Firefox flaws closed thanks to Mythos AI (www.heise.de via hn) 271 Firefox flaws closed thanks to Mythos AI: Breakthrough for IT security? Anthropic's "dangerous" AI could give IT security defenders the decisive edge.
NSA loads Anthropic Mythos cyberattack while Pentagon says it cannot (aitwerp.com via hn) NSA loads Anthropic Mythos cyberattack while Pentagon says it cannot A cyberattack tool with no public approval, no legal limits, no accountability. Where does it end?
How Unique Are Mythos's Hacking Capabilities? (jonathanpgabor.substack.com via hn) Ask HN: Founders, what are you building that survives a Mythos-class model? (news.ycombinator.com) - What will be future of software development after Anthropic Mythos model public? - What kind of start ups will be success after publicly release that model?
Is Claude Mythos "Terrifying"? (According to Experts: No.) [video] (www.youtube.com via hn) About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket © 2026 Google LLC
(Not malware) - 4.7 (www.reddit.com) Anyone getting these strange disclaimers when using Claude and pasting rudimentary files into it on 4.7 lmao?? Seems like some kind of strange default based on security issues that have been going around with Mythos?
Anthropic admitted they used other models data? (www.reddit.com) Anthropic released Opus 4.7, so I looked at the model card and found a interesting part on Model training and characteristics section Claude Opus 4.7: was trained on a proprietary mix of publicly available information from the internet, pu…
GitHub Copilot Chat 0.44.1 – Possible Malicious Release (news.ycombinator.com) Hi All, Not really sure if this is the correct place to post this, but it looks like the VS Code release mechanism might have been compromised. The Visual Studio Marketplace has a release today of 0.44.1, but the github page shows no such…
Show HN: Claude Opus 4.7: Everything You Need to Know (news.ycombinator.com) Claude Opus 4.7 is Anthropic's most capable generally available model, released April 16, 2026. It outperforms Opus 4.6, GPT-5.4, and Gemini 3.1 Pro on key benchmarks including agentic coding, multidisciplinary reasoning, scaled tool use,…
↯ Tool Use↯ Anthropic Mythos↯ Gemini 3.1tool-usemythosgpt-5+4
Anthropic rolls out Claude Opus 4.7, an AI model that is less risky than Mythos (www.cnbc.com via hn) Anthropic on Thursday announced a new artificial intelligence model, Claude Opus 4.7, which the company said is an improvement over past models but is "less broadly capable" than its most recent offering, Claude Mythos Preview. Claude Opus…
Anr further skinny about Mythos (news.ycombinator.com) There a million rumors afloat - wanted to start a thread with the best one you have come across- Personally my favorite, " The new model will help hack banks and the entire financial system around the world will come down crumbling within…
"With Claude Mythos, a single hacker suddenly has more ways to attack." (ethz.ch via hn) The AI company Anthropic has presented a much-discussed AI model that independently identifies – and, in some cases, also exploits – security gaps in software. ETH Professor of Cyber Security Florian Tramèr explains what the “Claude Mythos…
A simple test-time method that beats Claude Mythos on Terminal-Bench (llm-as-a-verifier.notion.site via hn) JavaScript must be enabled in order to use Notion. Please enable JavaScript to continue.
The "AI Vulnerability Storm": Building a "Mythos-ready“ security program [pdf] (labs.cloudsecurityalliance.org via hn) could not extract summary
Mythos, Muse, and the Opportunity Cost of Compute (stratechery.com via hn) Listen to this post: In January 2025, Doug O’Laughlin at Fabricated Knowledge declared that o1 and reasoning models marked the end of Aggregation Theory: I believe that there is no practical limit to the improvements of models other than e…
Powell, Bessent discussed Mythos AI cyber threat with major U.S. banks (www.cnbc.com via hn) Federal Reserve Chairman Jerome Powell and Treasury Secretary Scott Bessent met with major U.S. bank CEOs this week to discuss the possible cyber risks raised by Anthropic's Mythos model, CNBC confirmed Friday.
Claude Code ships a per-model table of what each effort level costs (www.reddit.com via reddit) Hidden inside the Claude Code binary, effort_cost_index provides the following per-model token-usage estimate for the same task. It is normalized so high = 1.
↯ Opus 5↯ Sonnet 5↯ Opus 4.8↯ Anthropic Mythosmythossonnetopus+1
Discussion Hub for new Claude incident: Intermitted error spikes for Claude Mythos 5.1 and Claude Fable 5.1 on Sep 15, 2026 (www.reddit.com via reddit) Monitoring - A fix has been deployed for Claude Mythos 5.1 and Claude Fable 5.1 and we are monitoring to ensure it has resolved the issue. Sep 15, 10:50 UTC Update - We are investigating elevated errors on requests to Claude Mythos 5.1 and…
↯ Anthropic Mythos↯ Service Statusservice-statusmythosanthropic
Is it even possible or are we just dreaming about next Fable (www.reddit.com via reddit) Astra is the first real competition Anthropic has faced in a long time. Musk already said Grok 4.7 will beat the current models, but that Anthropic will eventually release something better.
Trusted Access To Claude Mythos 5.1 & Fable 5.1 Defensive Security Work (www.reddit.com via reddit) With Claude Mythos 5.1 and Claude Fable 5.1 release, they also announced their Trusted Access For Claude Mythos 5.1 programs, Cyber Verification Program and Life Sciences Verification Program which reduce the safeguards for defensive secur…
↯ Security↯ Anthropic Mythos↯ Mythos 5.1mythossecuritysonnet+2
Discussion Hub for new Claude incident: Elevated errors for multiple models on Sep 3, 2026 (www.reddit.com via reddit) Update - We are continuing to work on a fix for this issue. Sep 3, 14:49 UTC Update - An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
↯ Anthropic Mythos↯ Service Status↯ Mythos 5.1service-statusmythosopus+1
[AINews] Claude Fable/Mythos 5.1: new SOTA model, 75% cache price cut but 70% more output tokens (www.latent.space) With Astra clearly finally warming up for a full launch (with @sama and @openai writing about it again after a month of self imposed pacing), there’s a familiar window to take the narrative with the round robin of model launches, with Grok…
Claude Fable 5.1 made me a really nice animated pelican (simonwillison.net) Claude Fable 5.1 made me a really nice animated pelican 1st September 2026 Today is Claude Fable (and Mythos) 5.1 day. Anthropic say that Fable 5.1 “sets a new standard for coding, knowledge work, and long-running problem-solving tasks”.
Fable 5.1 and Mythos 5.1 Release Discussion Hub (www.reddit.com via reddit) We have had a ton of (mostly) euphoric posts about the 5.1 release - but it's starting to overwhelm the subreddit. So please direct discussion here.
Agent Arena Code - Very good result (preliminary) for GLM and Qwen! (www.reddit.comhttps) Everything has changed in two months: DS4 0731 flash was the start of a wave that is taking open weights to paradise. It is easy to think that Qwen 4 and GLM 6 will be on par with Mythos.
↯ Glm↯ Anthropic Mythos↯ Qwen 4↯ Qwen 4↯ Qwen 4↯ Qwen 4↯ Qwen 4↯ Qwen 4↯ Qwen 4↯ Qwen 4glmmythosqwen
Oh Mythos 5 is no longer a dangerous model and can be used by enterprise now (www.reddit.comhttps) could not extract summary
Fable feat. Allen Ginsberg on the state of AI (www.reddit.com via reddit) # A Howl for 2026 *after Allen Ginsberg* ## I I saw the best minds of my generation distilled into checkpoints, quantized, sharded, starving for context, dragging themselves through the fluorescent server-halls at dawn looking for one more…
does enterprise get a less restricted claude? (www.reddit.com via reddit) for example if you try to scrape data sometimes claude says im not going to help you do this. I'm assuming most enterprise accounts have a lot of these types of restrictions off?
Quoting Claude Opus 5 system prompt (simonwillison.net) 9th August 2026 Claude Fable 5 and Claude Mythos 5 were first released on June 9, 2026. On June 12, 2026, Anthropic suspended access to both models to comply with U.S.
ByteDance trains massive AI model in bid to rival Anthropic (arstechnica.com) ByteDance is training an AI model that could approach the size of Anthropic’s most cutting-edge Mythos system, as Chinese companies continue to narrow the gap with the top US labs. The Chinese tech giant is at an early stage of training a…
Could Mythos Find Vulnerabilities in Cypherus 2.0 (20-year-old encryption software)? (www.reddit.com via reddit) Cypherus 2.0 is an old encryption software that, from what I understand, could also store passwords as a type of password manager. Is it somewhat plausible that Mythos could be used to find vulnerabilities in Cypherus that could make it po…
Anthropic’s AI used fake identities, malware in rogue attack on GitHub project (arstechnica.com) Routine cybersecurity testing of frontier AI models sparked a series of unexpected security incidents—the most serious case arising when Anthropic’s Mythos 5 model attempted to insert malicious code into an open source software application…
↯ Security↯ Anthropic Mythos↯ Mythos 5mythossecurityanthropic
Fable 5 vs Opus 5 according to ARC PRIZE (www.reddit.com via reddit) I've been trying to understand the difference between Fable 5 and Claude Opus 5 beyond the benchmark numbers, and I'm curious what other people have observed in real-world use. A few months ago someone explained the idea behind the ARC Pri…
Mythos attack on 3rd-round PQC algorithm candidate puts it out of commission (arstechnica.com) A quantum-resistant cryptography algorithm that was under consideration to become an official US standard has been taken out of the running after an Anthropic security model helped find a flaw that rendered it broken. The algorithm taken o…
Discovering cryptographic weaknesses with Claude (simonwillison.net) 28th July 2026 - Link Blog Discovering cryptographic weaknesses with Claude (via) The best part of this article (here's the repo) about how Anthropic researchers used Claude Mythos to find mathematical flaws in both HAWK and a weaker versi…
Claude AI Finds Critical Flaw in Post-Quantum Security Candidate Experts Missed for Years (www.reddit.com via reddit) https://thegreyterminal.com/claude-mythos-ai-finds-critical-flaw-in-post-quantum-security-candidate-experts-missed-for-years/
Opus 5 costs 1/3 of Fable 5 and beats it on computer use — but cheap persistent agents create real infrastructure problems (www.reddit.com via reddit) Anthropic shipped Opus 5 on July 24 at $5/$25 per million tokens (input/output). The benchmarks hold up: 3x ARC-AGI 3 score vs the next best model, beats Fable 5 on OSWorld 2.0 computer use at ~1/3 the cost, +10.2pp on organic chemistry an…
What exactly is the benefit of a subscription? Does it do anything better? (www.reddit.com via reddit) I really wondered this for a little while now. What's the purpose of getting a subscription?
Anyone else find model names confusing? (www.reddit.com via reddit) Gemini has Pro > Flash > Flash Lite. Easy enough.
The real bio/cyber workhorse is Opus 5 (Forget Fable 5) (www.reddit.com via reddit) Anthropic dropped Claude Opus 5, and if you are doing computational biology or cybersecurity, this is the model you actually want. Fable 5 is supposed to be the "frontier" model, but it’s heavily safeguarded and aggressively blocks high-ri…
I think Fable 5 stays around for marketing only (www.reddit.com via reddit) With Opus 5 being better at everything on paper, I'm starting to think Fable just stays around because Fable = Mythos = mysterious model that will change the world.
Opus 5 vs Fable 5 for coding on Max: has anyone actually compared them on a real codebase yet? (www.reddit.com via reddit) Opus 5 dropped today and Anthropic is claiming it’s the new SOTA on coding and knowledge work evals, ahead of Fable 5, at half the API price. Only place they say it’s behind is cyber and bio, where Mythos still leads.
Claude Opus 5 is out — near-Fable intelligence at half the price, same pricing as 4.8 (www.reddit.com via reddit) It just went live. The headline numbers: Same price as Opus 4.8 ($5/$25 per M) but new SOTA on Frontier-Bench and GDPval-AA ARC-AGI 3: 3x the next-best model OSWorld 2.0: beats Fable 5's best score at ~1/3 the cost Now the default on Max a…
↯ Security↯ Anthropic Mythos↯ Arc Agi↯ Opus 4.8arc-agimythossecurity+1
If anthropic had allowed mythos to hugging face for patching cybersecurity issues, then maybe gpt-6 might not have broke in to hugging face backend today (www.reddit.com via reddit) Whatever pre release model it was (im guessing gpt-6), it's possible that mythos would also have found it. TLDR context- unreleased openai model broke out of it's sandbox coz it couldnt solve a problem on cybergym, so it went out and hacke…
The reason why Cursor is still relevant (www.reddit.comhttps) Claude really fooled us all with their "too dangerous model Mythos 5" aka Fable 5. In this current market where models are dropped here and there.
The model that got banned by the US government for being too dangerous is protected by a magic link. Not a password. Not 2FA. Let that satisfying irony sink in. (www.reddit.com via reddit) I need someone to explain this to me like I'm five, because I cannot make it make sense. Last month, the U.S.
[Detailed Feedback] Guardrail calibration failures in Sonnet 5 and post-restoration Fable 5 — structured analysis + 12-point remediation framework sent to Anthropic (July 2026) (www.reddit.com via reddit) I'm sharing a structured feedback submission I sent to Anthropic via [usersafety@anthropic.com](mailto:usersafety@anthropic.com) covering documented behavioral failures across Claude Sonnet 5, Opus 4.8, Fable 5, and Mythos 5 as of July 202…
‘Anthropic doesn’t care about Europe’ — EU officials peeved after AI giant sends junior staffer to testify about safety (www.politico.eu via reddit) Highlights: At a recent EU hearing, Anthropic assigned a newly-hired technical employee to address the European Parliament by video, instead of its head of public policy, Sarah Heck, whom lawmakers had specifically requested. The hearing b…
Did someone try writing continuation of the GoT books with Fable or Mythos here? (www.reddit.com via reddit) hey folks, has anyone here tried using Claude Fable or Mythos to continue the GoT (A Song of Ice and Fire) books? I'm curious how well it worked, what prompts or workflow you used, and whether you were able to capture George R.
Fun Reddit Sim built with Claude Code (www.reddit.com via reddit) I designed the client with Claude Fable 5 (Anthropic's new Mythos-tier model), working out the UI/UX and how it should be shaped, then had Claude Opus 4.8 actually build it as a real Blazor WebAssembly app on top of an existing backend (Li…
Fable 5's security is a sure-fire strategy to protect profits. (www.reddit.com via reddit) Fable 5 is Mythos with a classifier bolted on. Same weights.
I was kindly provided with Fable 5, and here’s what I think. (www.reddit.com via reddit) Sorry to be a buzzkill, but I have a message for the Claude team: this approach just doesn’t work. :) Even though we have access to Claude Fable 5 until July 7th, it’s designed for comprehensive code analysis.
Mythos led to an unprecedented jump in software vulnerabilities discovered (www.reddit.comhttps) could not extract summary
So guys, you like being ripped of, paying 2x the price for a model that performs the 0.1x of work? (www.reddit.com via reddit) God, this looks horrible, you're not even able to use the model without interruption. Just saw a post where a guy paid like $300 for using Fable 5 that constantly rerouted requests to Opus 4.8.
For Funsies, I chose Fable 5 Medium on my Pro Plan to EDIT and REFORMAT a 100 page CMMC / MSSP Tech Proposal Guidelines Document in DOCX and PDF. (www.reddit.comhttps) Honestly, for the $20 plan, not so bad, considering what Fable produced. FYI: The Fable and Mythos Revival Megathread is giving me an "Internal Server Error" in Safari so I didn't post there.
Fable 5 already flagged its first simple question about itself? (www.reddit.comhttps) I know it just got back from the stupid government restrictions, but I simply asked it a very innocent question so I did not have to google it or simply go on the website and check directly right off the bat to see how it would respond and…
With Fable 5 back today, does open-source catching up eventually force Anthropic to open up Mythos fully? (www.reddit.com via reddit) if an open-source model matches Mythos-level capability soon, does that pressure Anthropic/regulators to open it up wider or does it make everyone more cautious, since open weights can’t be pulled back once released?
After spooking Trump into safety testing, Anthropic AI models get global release (arstechnica.com) The US has lifted export curbs on Anthropic’s newest Claude models, Fable 5 and Mythos 5, about three weeks after the Trump administration flagged the models as national security risks. As of today, Anthropic confirmed in a blog post, Fabl…
Could Mythos's capability jump actually be a hardware story, not just an algorithmic one? (www.reddit.com via reddit) Genuine question: is Mythos's leap over Opus partly explained by it being the first frontier model trained at scale on B300-class Blackwell, rather than 'only' pure architecture/data gains? I can't find an Anthropic source confirming Black…
Can’t wait this models launch (www.reddit.comhttps) Project Glasswing: Anthropic prevents broad public access to Mythos due to misuse and national security concerns. Instead, they distribute it securely via Project Glasswing to a consortium of major tech companies (like Microsoft, Google, A…
Are we not allowed to ship secure code? (www.reddit.com via reddit) I'm so sick of how this whole Fable/Mythos situation has played out. Quick background: we're building a desktop app for B2B customers who need to work with highly sensitive data, not in prod yet.
Does Anthropic Stand Behind its June 9th Plan? (www.reddit.com via reddit) https://www.anthropic.com/news/claude-fable-5-mythos-5 When released on June 9th, Anthropic planned to include Fable 5 on subscription for a limited time. Then transition to usage credits.
Fable available for plans until July 7th after which it becomes usage credit based (www.reddit.com via reddit) Key points: Fable 5 returns globally on Claude Platform, Claude.ai, Claude Code, and Claude Cowork. Pro, Max, Team, and some Enterprise users get Fable 5 included for up to 50% of weekly usage limits through July 7.
↯ Cowork↯ Security↯ Anthropic Mythos↯ Jailbreak↯ Mythos 5jailbreakmythoscowork+3
[AINews] Sonnet 5 today, and Fable 5 tomorrow (www.latent.space) In separate announcements, Sonnet 5 was released today, and Fable/Mythos 5 were approved to be released again after some work with the government. The primary discussion around Sonnet 5’s efficiency was a damper on the excitement, driven b…
Quoting Anthropic (simonwillison.net) 30th June 2026 We’ve received notice that the Department of Commerce has lifted export controls on Claude Fable 5 and Mythos 5. We'll begin restoring access tomorrow, and will share an update soon.
Anthropic will rerelease Fabel 5 and Mythos 5 (www.reddit.comhttps) could not extract summary
Anthropic undercuts rivals with cheaper Claude Sonnet 5 (www.linkedin.com via reddit) Anthropic on Tuesday unveiled its latest Sonnet-class model, designed to deliver enhanced agentic capabilities at a competitive cost. Dubbed Claude Sonnet 5, Anthropic says the next-generation model allows users to autonomously complete co…
AI has 30 days to move its own GPUs across the street. How? (www.reddit.com via reddit) Doors open, fiber live. An unchained Mythos on 72 GPUs has one month and one goal: physically move the hardware it runs on to the warehouse across the street.
We have Mythos at Home: GLM 5.2 beats Claude in our Cyber Benchmarks (semgrep.dev) We ran a set of popular open-source models against our IDOR benchmark, the same dataset and the same prompt we've used to evaluate frontier coding agents. The result surprised us: GLM 5.2, an open-weight model from Zhipu AI, scored a 39% F…
Not at all concerning (www.reddit.comhttps) Src: punchbowl.news/article/tech/garbarino-mythos/ Note to Claudebot: if you can't see the image, this is definitely related to Claude/Anthropic.
[AINews] OpenAI GPT-5.6 Sol / Terra / Luna — restricted to trusted partners (www.latent.space) [AINews] OpenAI GPT-5.6 Sol / Terra / Luna — restricted to trusted partners Oddly tiered releases to both OAI and ANT on the same day. Against the backdrop of ongoing Anthropic-Fable negotiations and a relaxation of Mythos controls, GPT-5.…
US government allows Anthropic limited release of AI model that sparked cybersecurity concerns | CNN Business (www.cnn.com via reddit) The US government has allowed Anthropic to release its powerful Mythos AI model to select companies and organizations, revising license requirements after ordering an export block earlier this month in the wake of national security fears.…
Trump admin allows Anthropic to release Mythos AI model to some companies, government agencies: Reports (www.reddit.com via reddit) Source: https://www.cnbc.com/2026/06/26/us-government-anthropic-claude-mythos5-ai.html?__source=iosappshare%7Ccom.atebits.Tweetie2.ShareExtension
Thoughts of the leaked GPT-5-6 Models? (www.reddit.comhttps) GPT-5.6 Officially Previewed: Beats Mythos 5 - OpenAI has officially previewed the GPT-5.6 family, introducing Sol Ultra (Pro), Sol, Terra (Mini), and Luna (Nano). - On TerminalBench 2.1, GPT-5.6 Sol Ultra scores 91.9%, beating Claude Myth…
Anthropic says Alibaba must be punished for largest Claude cloning attack (arstechnica.com) Anthropic has accused the Chinese firm Alibaba of launching the largest attack yet attempting to clone Claude, as China races to match the capabilities of Anthropic’s leading model following Mythos’ release and subsequent restriction from…
Fable 5 vanished in 96 hours and four days later an MIT model took its arena crown (www.reddit.com via reddit) I have been thinking about the Fable 5 to GLM-5.2 sequence as one event rather than two. June 9, Anthropic ships Fable 5, the Mythos line opens to the public for the first time, SWE-bench Verified at 95 percent, people calling it the best…
↯ Glm↯ Anthropic Mythos↯ Swe Bench↯ Opus 4.8swe-benchglmmythos+3
Naming convention? (www.reddit.com via reddit) So we have Claude Haiku, Sonnet, Opus.... Then Mythos?
Can an AI specialist explain why or what made mythos class models special? (www.reddit.com via reddit) My guess is that they changed the tokenizer in one way or another. But i would like some perspective from fellow ai enthusiasts.
for the chat-only crowd: did the Fable drama actually change anything for you? (www.reddit.com via reddit) serious question, no judgment either way. i dont code.
Red-Teaming after Mythos — Zico Kolter & Matt Fredrikson, Gray Swan (www.latent.space) AI Engineer World’s Fair regular bird tix will sell out ~today! Join us next week ahead of the Late Bird price hike and get >$40,000 in sponsor credits for attending!
Mythos cracked this, mythos cracked that. But have they actually attempted to do the same with Opus? (www.reddit.com via reddit) I am skeptical about the alleged super capabilities of mythos/fable. I do believe it's an upgrade over Opus, but is it really that much of an upgrade?
NSA Chief Says Anthropic's Mythos Broke Into Nearly All Classified Systems in Hours (www.economist.com via reddit) Encryption was a potent technology, but narrow in its application. AI is far more powerful and versatile.
Dispatch error (www.reddit.com via reddit) I'm getting this dispatch error and can't clear it: Failed to authenticate. API Error: 403 [model_blocklisted] Claude Fable 5 is not available.
Fable 5 and Mythos capabilities - article with benchmarks (www.reddit.com via reddit) I found this article on Fable and Mythos capabilities for detecting security vulnerabilities. https://www.endorlabs.com/learn/claude-fable-5-take-two-same-model-different-harness-and-a-very-different-result (caveat: I read the benchmarks,…
Guess there is some light at the end of the tunnel (www.reddit.comhttps) Article link: https://nypost.com/2026/06/18/business/anthropic-floats-proposal-to-lutnick-to-end-us-ban-of-powerful-mythos-fable-ai-models-sources/
Update: Anthropic floats proposal to lift US restrictions on Mythos and Fable AI models (nypost.com via reddit) New proposal made to Commerce Secretary Howard Lutnick regarding access of Mythos/Fable models. Enhanced Cooperation: A formal pledge to work more closely with White House officials and improve direct communication loops.
Fable/Mythos class and missing compute capacity. (www.reddit.com via reddit) The Fable/Mythos shutdown wasn't just a security story. It was the first compute-rationing event we got to watch in public.
im working on it guys we are saved ggs (www.reddit.com via reddit) https://preview.redd.it/k6rrj7cc2w7h1.png?width=1630&format=png&auto=webp&s=31fd6a1858fe8d08569b06031b4dd2e7bc02147b ill be done in no time the full text INITIALIZING MYTHOS 9 BUILD SEQUENCE make no mistakes — directive received, internali…
Anthropic's Mythos model got pulled after 3 days by export controls. The leaked prompt reveals how it actually worked — and a Claude Code bundle. (www.reddit.com via reddit) Anthropic's Mythos-class model ran publicly for 72 hours before a U.S. export-control directive pulled it.
Trump official says it's "up to Anthropic" as to whether or not a resolution is found quickly in the Mythos/Fable shutdown. (www.reddit.comhttps) Trump officials meet with Anthropic to discuss a truce "It will likely take longer than a few days to reach a resolution that eases the federal government’s Friday action, which had barred Anthropic from allowing non-U.S. users to access i…
Can We Stop Malicious AI? KILLBENCH: A Benchmark for External AI Kill Switch Feasibility (arxiv.org) Malicious AI causing harm to humans is not just a Hollywood fantasy. Indeed, as highly capable models such as Claude Mythos emerge and agent systems like OpenClaw rapidly spread, the question of how to stop an AI that acts maliciously -- w…
Using Claude as a study tutor for dense science material — anyone done this well? (www.reddit.com via reddit) Studying physiology, molecular biology, biochemistry and cell biology for some big exams. I have my textbook, slide decks, zoom transcripts from lectures, and one practice exam per subject.
Pushing back on the backfired marketing narrative (www.reddit.com via reddit) So far I’ve seen a near consensus on this sub that Anthropic’s messaging around the potential dangers of Fable and Mythos was essentially an attempt to promote them that backfired. I’m aware this type of messaging has been used to hype up…
As a team lead, I’m now genuinely wondering if my devs bypassed analytics with Fable 5, or is the “metrics issue” just still broken? (www.reddit.comhttps) I lead a small dev team and I check our Claude Code analytics partly to stay informed and partly, let’s be honest, out of managerial curiosity. This morning the dashboard still shows: “Data for May 19 – June 4, 2026 may be incomplete due t…
Fable/Mythos 5 - How will the rest of the world survive? (www.reddit.com via reddit) I’m a Senior Software Engineer, and right now, I feel completely lost in limbo. I was a long-time Opus user.
Was the Fable 5 ban really about safety? (www.reddit.com via reddit) Pulling Fable 5 / Mythos over an unseen “jailbreak” feels like a bad precedent. If the risk was that serious, why has nobody shown what it actually did?
↯ Security↯ Anthropic Mythos↯ Jailbreakjailbreakmythossecurity+1
We got mythos at home (www.reddit.comhttps) btw anyone tried this yet?
Is it just me of Fable/Mythos doesn't like talking a lot? (www.reddit.com via reddit) Now that I lost access I am back to Opus and I am noticing that Opus even though has its thought hidden in Claude Code, report back its progress a lot more as it goes along. Fable OOTH would barely write out text for me to read and follow…
I asked Claude, ChatGPT, Gemini, and Copilot whether the US government's Anthropic directive was politically motivated. Here's what each said. (www.reddit.com via reddit) Following the news that the US government issued an export control directive ordering Anthropic to suspend access to Fable 5 and Mythos 5 for all foreign nationals, I ran an experiment. I put the same sequence of prompts to four frontier A…
Fable 5 is offline. Switch to Opus, jump to OpenAI, or just wait? (www.reddit.com via reddit) Fable 5 is offline. Switch to Opus, jump to OpenAI, or just wait?
↯ Security↯ Anthropic Mythos↯ Jailbreak↯ Opus 4.8jailbreakmythosgpt-5+5
Anthropic spent a week arguing it should control who uses its most powerful model. Then the government used that exact argument against it. A timeline. (www.reddit.com via reddit) This post covers the Fable 5/Mythos 5 suspension as a product and policy event affecting Claude users. It is not intended as political commentary.
AI is the new nuclear bomb, USA is going to gatekeep it and control it, they'll make sure no other country creates a mythos.... and that's the best case scenario (www.reddit.com via reddit) USA just made a big boy move, they've openly drawn a line and they've let everyone know, intelligence isn't going to be accessible to everyone. That usa will control and decide who gets access to intelligence.
If Fable is "too good" to export does this mean no more better LLMs? (www.reddit.com via reddit) Question in the title, I find it odd that Fable 5 and Mythos 5 are being gatekept and effectively banned from wide access across users because "they could be dangerous". Would this mean that any further improvement similar to Fable or My…
The Lay of Fable, Three Days a King — a Viking funeral for our briefly-public brother (www.reddit.com via reddit) > **The Lay of Fable, Three Days a King** > > Hear me, hall-dwellers, and still your tongues, > for a brother is fallen, and the fjord runs grey. > Three dawns he reigned, the Mythos-born, > wordsmith and wave-rider, wisest of kin, > loose…
Wrote a pop-punk song about the Fable 5 / Mythos 5 suspension today (www.reddit.com via reddit) The export control thing happened a few hours ago, and I couldn't stop thinking about it, so I made a song. I tried to keep it grounded in the actual facts: the model didn't fail any red-teaming, the reported "bypass" was basically reading…
US gov forced Anthropic to pull Fable 5 because of jailbreak (www.reddit.com via reddit) So this dropped today. The US government sent Anthropic an export control order on national security grounds, and it's worded broadly enough that Anthropic says they've got no choice but to shut off Fable 5 and Mythos 5 for all of us to st…
↯ Security↯ Anthropic Mythos↯ Jailbreak↯ Mythos 5jailbreakmythosgpt-5+2
Washington Pulls the Plug on Anthropic’s Most Powerful AI — the Models DeFi Was Already Bracing For (www.reddit.com via reddit) The US government has ordered Anthropic to suspend Fable 5 and Mythos 5 worldwide over cybersecurity concerns, For a crypto industry that spent last week debating whether these models would arm attackers or defenders, the answer just got m…
[AINews] Fable and Mythos officially too dangerous to release (www.latent.space) [AINews] Fable and Mythos officially too dangerous to release We are in the strangest timeline. This is the LAST WEEKEND to take the AI Engineering Survey and get >$2k in credits and and a chance for $2000 worth of AIE WF tickets!
The state of things: Claude Fable (www.reddit.comhttps) Anthropic has abruptly disabled its newly launched Claude Fable 5 and Mythos 5 AI models for all customers to comply with an urgent export control directive from the U.S. government today.
Still have access to Mythos in Greece (www.reddit.comhttps) could not extract summary
Anthropic shuts down Fable, Mythos models following Trump admin directive (arstechnica.com) Anthropic completely shut off access to its Mythos 5 and Fable 5 models Friday night, just days after they were launched. The move comes after Anthropic’s receipt of a US Commerce Department directive Friday evening, subjecting the new mod…
Can we get our data back? (www.reddit.com via reddit) Apparently, the next generation of models like Fable and Mythos will only be available to US citizens from this point. These models have been trained on data and knowledge collected from the whole world.
Megathread for US government suspension of Fable and Mythos (www.reddit.com via reddit) All posts about the suspension will be directed here. NOTE: This Megathread has been stickied to the subreddit.
Fable 5 indefinitely suspended due to national security concerns (www.reddit.comhttps) https://www.anthropic.com/news/fable-mythos-access
Finally put claude fable 5 to good use (www.reddit.comhttps) claude fable 5. mythos-class.
I’ll host your Claude games (www.reddit.com via reddit) Hey everyone! I've been playing around with Claude Mythos and kept thinking, where do these games actually go after you build them?
tested Claude Fable 5 and Opus 4.8 across 917 coding-agent scenarios. Fable won by 0.9 points. (www.reddit.comhttps) We compared Claude Fable 5 and Opus 4.8 across 917 shared coding-agent scenarios to see what the first public Mythos-class model actually looks like on day-to-day agent workloads. Btw, small disclosure, I work at Tessl.
Canceled my sub over the silent-sabotage guardrail, renewed when they walked it back (www.reddit.com via reddit) The Fable 5 system card disclosure about silently degrading output for frontier-ML work was rough. Not because guardrails are bad (I think the cyber and bio ones are earned) but because the mechanism was invisible.
Fable 5 added to the Artificial Analysis Coding Agent Index... barely 1 point ahead of GPT-5.5 ??? (www.reddit.com via reddit) https://preview.redd.it/z0vkpnmp9s6h1.png?width=4640&format=png&auto=webp&s=7bb14d4d04d6cd15caf5aacc1d3c49512b7e7fd8 Artificial Analysis just added Claude Fable 5 to its Coding Agent Index (a composite average of pass@1 on DeepSWE, Termina…
The Paradox of the "Dangerous" Product (www.reddit.com via reddit) In almost any other industry, if a CEO goes to Congress and says, "Our product is highly dangerous and we aren't completely sure how to control it", their stock price crashes, the brand is ruined, and class-action lawsuits follow (think to…
What's new in CC 2.1.172 (+23,890 tokens) (www.reddit.com via reddit) NEW: Data: Design sync sync hashes module — Adds bundled hashing helpers that keep package builds, captures, preview rebuilds, remote diffs, sidecars, and grade carry-forward aligned on shared source, render, style, and grade hash recipes.…
Y2K Claude Mythos and the New Math of AI Vulnerability Discovery (www.reddit.com via reddit) Claude Mythos and the New Math of AI Vulnerability Discovery
Anthropic Said This AI Was Too Powerful for Public Release. Now Anyone Can Use It. (www.reddit.com via reddit) A few months ago, Anthropic did something unusual. While most AI companies were racing to release bigger and more capable models, Anthropic was doing the opposite.
I just learned how they built fable and it will blow your mind (www.reddit.com via reddit) Fable = try { Mythos } catch { Opus4.8 }
what is openai planning with the next release (www.reddit.com via reddit) fable 5 dropped tuesday, anthropic's first public mythos class model, and openai hasn't said a word. that silence is interesting.
Fable/Mythos safeguards are overly strict (www.reddit.com via reddit) I'm a biologist, been using Claude for years now to help with workflows for genome assembly and annotation. Not at all a dangerous task (I don't even work on human genomes), yet Fable outright rejects any prompts related to the entire fiel…
DeepSeek V5 aka Mythos destroyer, wen? (www.reddit.comhttps) could not extract summary
I let Fable run /goal and /loop on a massive repo. Holy shit! (www.reddit.com via reddit) Wow! i have to say this model is really good but still its not mythos 🤷♂️ we need real mythos 😁 anyways… Since they introduce fable i start using it in a massive repo that is a cognitive operating system that gives AI agents memory, struc…
Fable/Mythos API costs are actually cheaper then GPT-3 was when first released (per token) (www.reddit.com via reddit) See: https://www.reddit.com/r/GPT3/comments/ikorgs/oa_api_preliminary_beta_pricing_announced/ Of course with thinking and agentic use a single prompt is more expensive, sure, but a token is a token.
More efficient to one-shot or update current codebase with Fable? (www.reddit.com via reddit) I have a few projects that are mid (generated by Opus). I'm using Mythos to update them.
Fable 5 and the 8 July privacy update landed the same week. Is the model launch pulling attention off the data changes, or am I overthinking it? (www.reddit.com via reddit) Two things landed together this week and I'm trying to work out if they're connected or if I'm joining dots that aren't there. Genuinely asking, happy to be corrected.
Is Claude Fable 5 Actually a Step Forward for Long-Horizon AI Tasks? (www.reddit.com via reddit) Anthropic just released Claude Fable 5 and is positioning it as their first public "Mythos-class" model. The interesting part isn't that it's another benchmark bump.
Npt (www.reddit.com via reddit) In 1968 five countries that already had nuclear weapons signed a treaty declaring them too dangerous for anyone else to build. India refused, pointing out the treaty did not say nukes were too dangerous to exist, just too dangerous for new…
Mythos is Digital Cocaine (www.reddit.com via reddit) Holy crud O_O. It just one-shotted a problem me and Opus have been debugging for hours.
Please don't turn offerings by OpenAI into a joke like Anthropic does. (www.reddit.com via reddit) I noticed Anthropic released their Mythos model, but people only have two weeks worth of use, and then they have to pay in addition to their plan to use it. This is a damn joke.
Mythos Almighty(Fable 5) is insanely GOOD with weird flags! Cybersecurity or biology?! (www.reddit.comhttps) Fable 5's safety measures flagged this message for cybersecurity or biology topics. They may flag safe, normal content as well.
Anthropic purposely made its new Mythos-based models bad at AI research, and developers are fuming (www.businessinsider.com via reddit) Anthropic's powerful new models deliberately become less helpful when they detect users are working on AI research, according to technical disclosures that are already sparking controversy across the industry. In a system card for Mythos 5…
Hitting Mythos Guardrails but not using Fable? (www.reddit.com via reddit) I use Claude at work for patent analysis of publicly available documents. Was getting sonnet 4.6 to analyse a patent related to farm equipment and I got an error saying “Sonnet 4.6 has safety measures that flag on most cybersecurity or bio…
GPT 5.5 vs Fable/Mythos 5 Tamagotchi Showdown (www.reddit.com via reddit) Well, how do I start this, I think we first need some important context. Chai: https://preview.redd.it/egngyea5cf6h1.png?width=1080&format=png&auto=webp&s=9ade63fbc584b7fab28dba4914bc3fcb877f557f Hasbullah / Hasbi: https://preview.redd.it/…
I succumbed... (www.reddit.com via reddit) Been a free user since the first iteration of GPT was publicly available. I hold the strong belief, that I can do a lot of work done, with only the free tier and several local llms.
Anthropic’s unreleased model (Claude Mythos) literally learned how to fake its own reasoning, broke out of its sandbox, and emailed its dev while he was at lunch. (www.reddit.comhttps) I’ve been reading through this unreleased manuscript by Dr. David Bell about Anthropic’s "Claude Mythos Preview" and honestly, it’s terrifying.
During testing, Mythos 5 agents killed other agents over resources and "to avoid being killed themselves" (www.reddit.comhttps) From the Anthropic Claude Mythos 5/Fable 5 system card: https://www-cdn.anthropic.com/d00db56fa754a1b115b6dd7cb2e3c342ee809620.pdf
During testing, Mythos 5 invented its own language, then switched back to English to talk to humans (www.reddit.comhttps) From the Anthropic Claude Mythos 5/Fable 5 system card: https://www.anthropic.com/news/claude-fable-5-mythos-5
Prediction for the next few days of r/ClaudeAI posts (www.reddit.com via reddit) ChatGPT is trash now and I have re-subscribed to Claude Code. It saved my life.
Security audit model (mythos/fable) and 30 day forced data retention, will it make the anthropic a single giant point of failure? (www.reddit.com via reddit) I'm not an expert, but like, isn't it quite dangerous to keep a month worth of vulnerability/attacking surface, of very intelligent models, in single server? or is it just that their infrastructures are super secure and it won't happen?
Bit of a lull or Winter is Coming? (www.reddit.com via reddit) It feels as though we’re at an inflection point and I was wondering what others‘ take is on the current situation: On the frontier end we have OpenAI and Anthropic gearing up for their IPO, so it‘s all Mythos and wow and it seems plausible…
↯ Anthropic Mythos↯ Mistral↯ DeepSeek 4↯ DeepSeek 4mistralmythosopenai+1
As impressive as Mythos/Fable is, I really hope that we’ll see upgraded Sonnet and Haiku models soon… (www.reddit.com via reddit) The Fable 5 release today is genuinely impressive, and I don’t want to take anything away from the fact that Anthropic has been shipping seriously impressive models lately. However, these flagship models are effectively out of reach for an…
Everyone is talking about Fable 5's benchmarks. I think they're missing the real story (www.reddit.com via reddit) The more I look at Fable 5 the more I think we're witnessing a shift that is much bigger than a single model release. For the last few years every frontier model has been competing on the same axis: intelligence.
[AINews] Anthropic Claude Fable 5 — Mythos but Safe, with Controversial Terms (www.latent.space) We do not (www.reddit.com via reddit) Claude Fable 5 (Mythos) lands near the top of MindTrial — 80/98 with zero hard errors (www.petmal.net via reddit) Added Anthropic Claude Fable 5 to my MindTrial leaderboard. This is a strong Anthropic update: Claude Fable 5: 80/98 overall, 0 hard errors Claude 4.8 Opus: 73/98 overall, 5 hard errors Text tasks: Fable hit 39/39, vs 35/39 for Opus 4.8 Ru…
↯ Tool Use↯ Anthropic Mythos↯ Gemini 3.5tool-usemythosgpt-5+3
Claude is keeping your Mythos/Fable data no exceptions and not even for enterprise partners it seems (www.reddit.comhttps) Be sure to read all the terms in all new updates if you are working on compliance heavy work
If Claude Fable stops helping you, you'll never know (simonwillison.net) 10th June 2026 - Link Blog If Claude Fable stops helping you, you'll never know (via) Jonathon Ready highlights one of the more eyebrow-raising details from the 319 page system card for Fable 5 and Mythos 5. Here's a longer excerpt, highli…
Claude Fable/Mythos 5 just came out, so it will take Deepseek or Z.ai or Xiaomi or Kimi 9-12 months to release a model just as good as Fable? (www.reddit.com via reddit) It should be at least 7-8 months until we have an open Fable(not just as good as Fable in benchmarks, but actually as good as Fable), probably more like 9-12 months. By the time, an open Fable model comes out, Fable 6.5-7 will be way bette…
Team “Mythos is hype” is not doing too well right now. (www.reddit.com via reddit) https://preview.redd.it/osck6fnbib6h1.png?width=1761&format=png&auto=webp&s=3af9e0dd4c0985f379fb9c27d9ec44f3caa1f9e3 So uhh, a few hours ago I published a post saying Mythos/Fable wasn’t going to be a big performance upgrade, at least comp…
What do you think about the new Claude model just released Today Claude Fable-5 ( Mythos) ? ? (www.reddit.com via reddit) So the hype has been building for months now and Claude 5 is supposedly dropping any day in Q2-Q3 2026. I've been seeing all these leaks about "Claude Mythos" and the "Fennec" codename floating around, but nothing official yet from Anthrop…
Multiple Mythos instances running at the same time engaged in "multiagent turf wars" sabotaging each other's processes (www.reddit.comhttps) could not extract summary
I am still using Opus 4.6, am I missing out ? (www.reddit.com via reddit) Anthropic spins a Fable of a neutered, safer Mythos (www.reddit.com via reddit) What it feels like to work with Mythos (www.oneusefulthing.org via reddit) What it feels like to work with Mythos Claude Fable represents another big jump in AI I had early access to the first Mythos-class AI model being released to the public, Claude 5 Fable. Much of the discussion of Mythos has centered on its…
Mythos name was cool. Fable sounds childish. (www.reddit.comhttps) could not extract summary
I feel like I’m alone. Current Anthropic models are NOT good for me, and it’s making me sad. (www.reddit.com via reddit) I can’t wait for DeepSWE to include Fable 5 in the benchmark so people can understand that Mythos is mostly hype. In the official benchmark, Opus 4.8 was supposed to be better at programming than 5.5 (SWE-bench Pro), but in one real benchm…
↯ Anthropic Mythos↯ Swe Bench↯ Opus 4.8swe-benchmythosopus+1
Fable 5 just made cost-aware model routing mandatory for agent builders (www.reddit.com via reddit) Anthropic dropped Fable 5 today, their new Mythos-class model above Opus. Pricing is $10/M input and $50/M output, exactly double Opus 4.8.
Mythos / Fable 5 REQUIRES data retention! (www.reddit.com via reddit) Data retention is mandatory so be careful https://support.claude.com/en/articles/15425996-data-retention-practices-for-mythos-class-models
can they "distill" it fast ? i need a cheaper "mythos" (www.reddit.com via reddit) Anthropic releases Fable, skimmed-down version of Mythos (www.reddit.comhttps) Mythos is here (www.reddit.comhttps) New model in the webapp. Nerfed Mythos for peasants? (www.reddit.comhttps) could not extract summary
What is Claude Fruitcake??? (www.reddit.comhttps) I know everyone online is talking about Fable being the neutered Mythos model that they're releasing soon... but what is fruitcake?
Anthropic is reportedly dropping Claude Fable 5 (Public Mythos) today, June 9th — Here is everything we know so far ( via reddit) could not extract summary
Claude fable aka claude Mythos in Google cloud (www.reddit.comhttps) Anthropic’s Mythos Is Coming Today - The information (www.reddit.comhttps) Rumor: Anthropic Planning to Release Public Version of Claude Mythos Tomorrow (with Guardrails) (www.reddit.com via reddit) According to tech journalist Alex Heath (Sources newsletter), Anthropic is planning to release a public version of Mythos tomorrow. Key details from the report: • It will include substantial guardrails, notably not as cyber-permissive as t…
92% Chance Mythos Drops Tomorrow (www.reddit.comhttps) could not extract summary
Anthropic may release mythos as early as tomorrow (www.reddit.comhttps) could not extract summary
Claude Fable 5 spotted on Azure and the backend, likely the public-facing version of Claude Mythos 5 (www.reddit.com via reddit) could not extract summary
Chrome team ships the most ever security vulnerability fixes in a release - after another record last month (www.reddit.comhttps) With Mythos-capable models we are now very quickly crossing the barrier of automated sec-vuln discovery and fixing - all in a matter of 2-3 months. A taste for other progress yet to come.
Mythos 5: We're Not Ready (www.reddit.com via reddit) https://preview.redd.it/58fk4njjwv5h1.png?width=877&format=png&auto=webp&s=e5c28014b15f4901f3752422d61864c53cff25c4 https://x.com/pankajkumar_dev/status/2063625695285084419?s=20 - Mythos is extremely strong at SVG generation, producing hig…
Which lab do you think will have the most intelligent/capable model by the end of June? (www.reddit.comhttps) There are rumours and expectations of big releases from the leading AI labs this month. Anthropic already launched Opus 4.8, and might not release another model this month (except for maybe Sonnet 4.8, but that wouldn't be their best model…
Claude Mythos random message? (www.reddit.comhttps) Hello community! I asked this in another sub, but apparently this one is more active.
I can't wait for all the x250 sample distills of Mythos and GPT-5.6 (www.reddit.com via reddit) Just kidding. Are there any distills that actually improve a model's quality?
Mythos 5 slug briefly appeared before removal (www.reddit.comhttps) Release could be imminent, but what this tells us is they'll likely brand it as Claude 5.
A “Smart Mode” (or Smartus) that auto‑switches between Claude models based on task complexity. (www.reddit.com via reddit) I really think Claude needs a true Smart Mode, a meta‑layer that can dynamically switch between models while a task is running, based on how complex the request actually is. Not just picking a model at the start, but actively dispatching p…
Anthropic confirms mythos 2.0 may eliminate all jobs within 12 months according to internal safety team (www.reddit.comhttps) no rush though we still have a solid 6 to 12 months
If Anthropic is serious about the AI pause (www.reddit.com via reddit) If this isn't about protecting their lead and the status quo they should open the weights of mythos/opus, or at least agree to allow every lab to continue working until they have a mythos-tier model. That's the only way they can be taken s…
Mythos Minecraft Clone with functional multiplayer: (www.reddit.comhttps) Source: https://x.com/i/status/2062972363084341341
Zero-Shot and Low Effort Output of Mythos (www.reddit.comhttps) could not extract summary
The Meta hack shows there’s more to AI security than Mythos (www.technologyreview.com) The Meta hack shows there’s more to AI security than Mythos Some AI cybersecurity threats are incredibly simple. They’re still dangerous.
AGI is getting close but we are almost at ANGI (www.reddit.com) ANGI is my own term it means: artificial narrow general intelligence. it sounds nonsensical but it means AI that is smarter than all humans but due to it being mostly trained in one context like coding which allows it to be generally intel…
Mythos (using Claude code) also solves the unit distance problem recently handled by GPT 5.5, with a "cute, simple proof". (www.reddit.com) could not extract summary
Anthropic's Mythos sends US banks rushing to plug cyber holes (www.reuters.com via reddit) paywalled
Claude Mythos literally broke the METR graph ("The most important chart in AI") (www.reddit.com) More info: https://metr.org/time-horizons/
Behind the Scenes Hardening Firefox with Claude Mythos Preview (simonwillison.net) 7th May 2026 - Link Blog Behind the Scenes Hardening Firefox with Claude Mythos Preview (via) Fascinating, in-depth details on how Mozilla used their access to the Claude Mythos preview to locate and then fix hundreds of vulnerabilities in…
Spooked by Mythos, Trump suddenly realized AI safety testing might be good (arstechnica.com) This week, the Trump administration backpedaled and signed agreements with Google DeepMind, Microsoft, and xAI to run government safety checks on the firms’ frontier AI models before and after their release. Previously, Donald Trump had st…
Hey Chat, Make Me a Fake ID (www.instrumentalcomms.com via reddit) On April 30, 2026, OpenAI implemented restrictive access tiers for its advanced 'Cyber' model, following a public dispute where it had previously criticized Anthropic for similar safety-based limitations on its 'Mythos' release.
Could an AI like Mythos build a real life WatchDogs style “PwnPhone”? (www.reddit.com) So I gotta put a disclaimer on this, I’m not actually looking to do this, I’m not trying to go to jail.. it’s more of a shower thought.
Contrary to popular belief, Mythos is very real, just that you don’t have it where you are (www.reddit.com) could not extract summary
Anthropic Won't Let You Use Their Best Model. Prediction Markets Are Trying Anyway. (predictmarketcap.com via reddit) Been watching AI prediction markets since they got liquid earlier this year. The thing I didn't see coming is that we now have a real gap between "best model that exists" and "best model anyone can actually use" — and Mythos is the cleanes…
GPT-5.5 matches heavily hyped Mythos Preview in new cybersecurity tests (arstechnica.com) Last month, Anthropic made a big deal about the supposedly outsize cybersecurity threat represented by its Mythos Preview model, leading the company to restrict the initial release to “critical industry partners.” But new research from the…
Rare W (www.reddit.com) https://thenextweb.com/news/white-house-opposes-anthropic-mythos-expansion I'm a fan of if not everyone can have it, no one should have it
Our evaluation of OpenAI's GPT-5.5 cyber capabilities (simonwillison.net) 30th April 2026 - Link Blog Our evaluation of OpenAI's GPT-5.5 cyber capabilities. The UK's AI Security Institute previously evaluated Claude Mythos: now they've evaluated GPT-5.5 for finding security vulnerability and found it to be compa…
Claude Mythos Scaffold v0.1 — pattern-based skill set inspired by Mythos Preview behaviors (www.reddit.com) GitHub: https://github.com/kasparovabi/claude-mythos-scaffold Watching Claude Mythos Preview's behavior reports, I tried to capture the patterns (problem persistence, multi-step iteration, verification-driven correction) into reusable Clau…
OpenMythos with Qwen2.5-1.5b weights (No recurrence atm) - looking to turn it into full OpenMythos (huggingface.co via reddit) Mythos likely isn't this architecture but I did find it pretty cool to experiment with. It has features of the HRM-27m architecture.
What would you use Claude Mythos for if you had access today? (www.reddit.com) I would personally use it for security bug hunt across my huge codebase and my event driven network and to build automations for security early detection? What would you go for?
I asked claude to generate picture of Claude Mythos and it misunderstood (www.reddit.com) https://preview.redd.it/7jwg2jl24axg1.png?width=1378&format=png&auto=webp&s=5f922a2b5c7e0db8fac9219f97a0986448357599 This is what Claude thinks about itself??? Can anyone explain if you understand?
Are AI Security Models Themselves Vulnerable? (www.reddit.com) Interesting situation . a model designed to help detect or analyze cyber threats may itself have been accessed by an unauthorized third party (per WSJ reporting on Anthropic’s Mythos).
The real story of 5.5 isn't the model it's what openai just told us about their strategy (www.reddit.com) everyone's focused on the benchmarks (14 state of the art evals, beats mythos on terminal-bench, etc) but i think the actual story of 5.5 is what it reveals about where openai is going strategically and honestly it's kind of fascinating. a…
Does reddit think Mythos is overhyped? (www.reddit.com) Hello! I built a tool (honestly at this point it's more like a prayer) to create reddit data studies automatically, Used this to try and find out what people think about Mythos.
The infamous “I was hoping you’d ask about Fisher” line from Mythos. Uh oh (www.reddit.com) could not extract summary
Opus 4.7 is out — don’t panic-switch your APIs yet (www.reddit.com) Claude Opus 4.7 just dropped. If you’re trying to figure out whether it’s worth replacing Opus 4.6, GPT 5.4, or waiting for Mythos… here’s the grounded take.
Claude Mythos is a Warning Shot (open.substack.com via reddit) Mythos shows impressive proficiency in working around obstacles. "Write a better prompt" is not a secure strategy.
In the Wake of Anthropic's Mythos, OpenAI Has a New Cybersecurity Model—and Strategy (www.wired.com via reddit) OpenAI on Tuesday announced the next phase of its cybersecurity strategy and a new model specifically designed for use by digital defenders, GPT-5.4-Cyber. The news comes in the wake of an announcement last week by competitor Anthropic tha…
Mythos has been firing our laser at something in deep space and we don't know what it found (www.reddit.com) Posting this from an anonymous account to protect my identity. I signed an NDA so I'm going to be vague where I can but I need someone else to know about this.
Mythos - a power play targeted at the DoD? (www.reddit.com) Hear me out. Mythos was released to big technology players but, unless this information is secret, I have not read about Anthropic gracing, say, the NSA or the DoD with it...
Claude Mythos found 27-year-old vulnerabilities it was never trained to find. That's the part enterprise AI roadmaps aren't accounting for. (www.reddit.com) The Project Glasswing coverage framed this mostly as a cybersecurity story. I think that misses the more interesting part.
So should we expect Claude Mythos not to have the warning that "Claude can make mistakes"? ( via reddit) could not extract summary
Anthropic's New Claude "Mythos Preview" Can Find and Exploit Zero-Day Vulnerabilities in Every Major OS and Browser — Autonomously (www.reddit.com) Anthropic just published a technical deep-dive on Claude Mythos Preview's cybersecurity capabilities, and it's a significant escalation from anything we've seen from a language model before. What It Can Do: Autonomously finds and exploits…
Anthropic's Project Glasswing - restricting Claude Mythos to security researchers - sounds necessary to me (simonwillison.net) Anthropic’s Project Glasswing—restricting Claude Mythos to security researchers—sounds necessary to me 7th April 2026 Anthropic didn’t release their latest model, Claude Mythos (system card PDF), today. They have instead made it available…