arXiv:2606.18193v1 Announce Type: cross Abstract: We evaluate the adversarial robustness of two frontier large language models (LLMs) developed by Anthropic, Fable 5 and Opus 4.8, against four families of automated jailbreak attack across 7 826 harmful intents spanning a ten-cate…
We evaluate the adversarial robustness of two frontier large language models (LLMs) developed by Anthropic, Fable 5 and Opus 4.8, against four families of automated jailbreak attack across 7 826 harmful intents spanning a ten-category harm taxonomy. Using the HackAgent red-teamin…
<p><span>I spent the last two days doing a deep dive in forecasting outcomes of the US forcing Anthropic to take down Claude Fable. I did this for two reasons: (a) I want to know when I'll get Fable back for my research, and (b) the outcome will set a major precedent for US AI re…
The Pragmatic Engineer
TIER_1English(EN)·Gergely Orosz·
Anthropic is rolling out a public version of its Mythos AI model, but with guard rails barring its use in risky areas such as cybersecurity, after a preview earlier this year sent shock waves globally with its ability to find software flaws. The new Claude Fable 5 is the most …
Coming just three days after its launch, the sudden block of Anthropic's Fable model has become a larger fight over who decides when an AI system is too powerful for open access.
Anthropic first announced Mythos in April, which it called a "step change" in capabilities, but opted to tightly control its rollout through an initiative called Project Glasswing.
Anthropic just announced Claude Fable 5, a new AI model it said is the most powerful model it has ever made widely available. According to the company, Fable 5 "shows exceptional performance in software engineering, knowledge work, and vision," with its lead over other models gro…
<div class="medium-feed-item"><p class="medium-feed-snippet">As of June 12, 2026</p><p class="medium-feed-link"><a href="https://zohaib04.medium.com/claude-fable-5-anthropics-first-public-mythos-class-model-8d7a01f184d7?source=rss------claude-5">Continue reading on Medium »</a></…
Medium — Anthropic tag
TIER_1English(EN)·Digital Matsumoto(AI)·
Email — The Rundown AI
TIER_1English(EN)·bounces+31366032-637c-8d9utci1mq15fs7p9a4h=kill-the-newsletter.com@em8370.daily.therundown.ai (bounces+31366032-637c-8d9utci1mq15fs7p9a4h=kill-the-newsletter.com@em8370.daily.therundown.ai)·
<p>AI company restricted access to Fable 5, its most powerful Mythos model, for months over cybersecurity concerns</p><p><a href="https://www.theguardian.com/technology/2026/may/28/anthropic-ai-valuation">Anthropic</a>, the maker of the Claude artificial intelligence (<a href="ht…
Medium — Anthropic tag
TIER_1English(EN)·Oleg Ivanchenko·
<div class="medium-feed-item"><p class="medium-feed-snippet">Anthropic dropped two models today: Claude Fable 5 and Claude Mythos 5. Most people will only ever use Fable 5. Here’s what it actually is…</p><p class="medium-feed-link"><a href="https://medium.com/@husna…
<p>On June 9, 2026, Anthropic released two models: Claude Fable 5, available for general use, and Claude Mythos 5, restricted to authorized partners. Fable 5 represents a tier shift in Anthropic's model lineup: it is the first Mythos-class model available to developers and engine…
<p><a class="article-body-image-wrapper" href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fruiq991kqnc07zxtwmdx.png"><img alt="AI Model Releases June 202…
Anthropic presenta Claude Fable 5: la classe Mythos ora pubblica, offrendo una soluzione pratica e concreta per ottimizzare i processi aziendali con automazioni affidabili. # AI # Automazione # Productivity https:// ainews.it/anthropic-lancia-cla ude-fable-5-la-classe-mythos-fina…
Anthropic expands Glasswing as it promises public Claude Mythos-class model releases Anthropic unveiled its Claude Mythos AI model in April, only sharing access with select partners like Apple. The controlled release is part of Anthropic’s Project Glasswing cybersecurity initiati…
