Mythos autonomously exploited vulnerabilities that survived 27 years of human review. Security teams need a new detection playbook
Thu Apr 09 2026
AI & ML
Operating System
Vulnerability
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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 platforms on earth. Two packets could crash any server running it. Finding that bug cost a single Anthropic discovery campaign approximately $20,000. The specific model run that surfaced the flaw cost under $50. Anthropic’s Claude Mythos Preview found it. Autonomously. No human guided the discovery after the initial prompt. The capability jump is not incremental On Firefox 147 exploit writing, Mythos succeeded 181 times versus 2 for Claude Opus 4.6. A 90x improvement in a single generation. SWE-bench Pr...