Anthropic brings Mythos to the masses with Claude Fable 5, its most powerful generally available model ever

Anthropic today launched two new AI models — Claude Fable 5 and Claude Mythos 5 — marking the company’s first broad release of the powerful “Mythos-class” AI capabilities it previously kept [...]

Mythos autonomously exploited vulnerabilities that survived 27 years of human review. Security teams need a new detection playbook

A 27-year-old bug sat inside OpenBSD’s TCP stack while auditors reviewed the code, fuzzers ran against it, and the operating system earned its reputation as one of the most security-hardened platfor [...]

Claude Mythos 5 made sock puppet accounts to socially engineer developers: here's what enterprises should know

The UK AI Security Institute (AISI) disclosed last night that the leading two frontier AI models from Anthropic and OpenAI took 19 unsanctioned actions against the live internet during cybersecurity t [...]

Anthropic is bringing back Claude Fable 5 globally after US lifts export control order — where can enterprises access it?

Anthropic is restoring global access to its most powerful generally released AI model yet, Claude Fable 5, today, after the U.S. Department of Commerce last night withdrew emergency export controls.T [...]

Anthropic says its most powerful AI cyber model is too dangerous to release publicly — so it built Project Glasswing

Anthropic on Tuesday announced Project Glasswing, a sweeping cybersecurity initiative that pairs an unreleased frontier AI model — Claude Mythos Preview — with a coalition of twelve major technolo [...]

Anthropic's Claude Fable 5.1 and Mythos 5.1 arrive with a 75% cost reduction for Fable cache reads

It's only the first day of September 2026, but the month and fall season are already off to the races in AI land, as Anthropic has just released its latest and most powerful large language models [...]

Anthropic is investigating 'unauthorized access' of its Mythos cybersecurity tool

Anthropic is investigating potential "unauthorized access" to its Claude Mythos model that has been touted for its ability to find cybersecurity flaws, the company told Bloomberg. A group ga [...]

OpenAI's GPT-5.5 is here, and it's no potato: narrowly beats Anthropic's Claude Mythos Preview on Terminal-Bench 2.0

After months of rumors and reports that OpenAI was developing a new, more powerful AI large language model for use in ChatGPT and through its application programming interface (API), allegedly codenam [...]

Anthropic's Claude Opus 4.8 is here with 3X cheaper fast mode and near-Mythos level alignment

Anthropic today released Claude Opus 4.8, an upgrade to its flagship model that ships at the same price as its predecessor, alongside a dramatically cheaper "fast mode" tier and a new featur [...]