Claude Claude Mythos 5
Our most capable model for cybersecurity and biology research.
Announcements
- NEW
Claude Mythos 5
Jun 9, 2026
Claude Mythos 5 is the latest update for Mythos Preview, seeing gains in cybersecurity, biology, and healthcare benchmarks. Given its capabilities, Mythos 5 is currently only available to a small group of vetted partners with a goal of opening up more broadly in the future.
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Expanding Project Glasswing
Jun 2, 2026
We’re extending Project Glasswing to approximately 150 new organizations in more than fifteen countries.
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Project Glasswing: An initial update
May 22, 2026
We and our approximately 50 partners have used Claude Mythos Preview to find more than ten thousand high- or critical-severity vulnerabilities across the most systemically important software in the world.
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Project Glasswing
Apr 7, 2026
Today we’re announcing Project Glasswing, a new initiative that brings together Amazon Web Services, Anthropic, Apple, Broadcom, Cisco, CrowdStrike, Google, JPMorganChase, the Linux Foundation, Microsoft, NVIDIA, and Palo Alto Networks in an effort to secure the world’s most critical software.
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Availability and pricing
Claude Mythos 5 is available to a small set of initial testing partners for cybersecurity, and soon, biology research. We aim to expand our trusted access programs to safely allow more organizations to secure their code and create life-changing research.
Pricing for Claude Mythos 5 starts at $10 per million input tokens and $50 per million output tokens.
Safeguards
Because Mythos 5 is highly capable for cybersecurity and biology research, it could be used both for good and for harm. We currently only provide access to a small, but growing, set of customers through our trusted access programs.
In order to release Mythos-level capabilities for knowledge work, coding, and more broadly we’ve added additional safeguards.
Claude Fable 5 is the same underlying model as Mythos 5 with robust safeguards for cybersecurity and biology. Queries in these domains are automatically routed to Opus 4.8. We extensively test and evaluate our models to ensure they meet Anthropic’s standards for safety, security, and reliability. The accompanying system card covers safety results in depth.
Data retention
Using Mythos 5 requires accepting a 30-day data retention policy for safety monitoring. Learn more.
Benchmarks
Claude Mythos 5 is state-of-the-art at cybersecurity, biology research, and healthcare.
Frequently asked questions
Making a model as capable as Mythos 5 generally available comes with risks. The model’s capabilities in specific areas like cybersecurity and biology are advanced enough that they could be misused to create cyberattacks or dangerous weapons. To release Mythos-level capabilities more broadly, we developed Claude Fable 5 with safeguards that block its performance in risky areas.
Our goal is to safely open up access to vetted partners for Mythos 5 dual-use capabilities. To stay up to date on our plans for trusted access programs for cybersecurity and biology research in Mythos 5, sign up for notifications.