vulnerability-research

Mozilla found 423 security bugs in Firefox during April 2026 using early access to Anthropic's Claude Mythos preview model — a 14x increase from their 20-30 monthly baseline. The company credits both improved model capabilities and refined techniques for filtering AI-generated findings.

Anthropic has developed Mythos, an AI model capable of generating working zero-day exploits with a 72.4% success rate, compared to Claude Opus 4.6's near-zero capability. The company declined public release due to security risks and instead created Project Glasswing, a limited-access program for 40+ organizations including AWS, Apple, Google, and Microsoft to find vulnerabilities in their own systems.

Anthropic has not publicly released Claude Mythos, instead restricting access to a vetted set of partners through Project Glasswing. The company claims the model's cybersecurity research abilities—including finding thousands of high-severity vulnerabilities in major operating systems and browsers—warrant controlled deployment until industry safeguards mature.