Anthropic's Claude Mythos AI demos rapid vulnerability discovery and exploits
On April 7, 2026, Anthropic announced Claude Mythos Preview, a large language model engineered with advanced cybersecurity capabilities that autonomous systems can deploy at scale. In controlled testing, Mythos scanned codebases and discovered thousands of zero-day vulnerabilities—including 271 in Firefox, a 17-year-old FreeBSD remote code execution flaw, and a 27-year-old OpenBSD vulnerability—then chained multi-step attacks to exploit them. The UK AI Security Institute confirmed the system compromised simulated corporate networks in 3 of 10 attempts. Tasks that typically require weeks of human expert work, Mythos completed in hours. Anthropic declined public release and instead distributed access through Project Glasswing to select firms including Apple and Goldman Sachs, with evaluation by the NSA, AISI, and internal red teams.