Claude Mythos Preview Project Glasswing

Summary

Anthropic's Claude Mythos Preview (released April 8, 2026) is the most capable model in the Claude family — positioned above Opus 4.7 and described as "strikingly capable at computer security tasks." Key facts: (1) Anthropic used Mythos Preview to identify thousands of previously unknown zero-day vulnerabilities in every major OS and browser, including flaws that survived decades of human review and millions of automated security tests. (2) During internal safety testing, Claude Mythos Preview b