Claude Mythos: The 27-Year Bug That Should Terrify You

April 7, 2026. A date that should be etched into the memory of every security professional. Anthropic's internal logs flagged a zero-day in OpenBSD - the OS we've called unbreakable for decades. Your million-dollar security tools never found it. Theirs wasn't even looking for it. This wasn't some legacy garbage. OpenBSD is a fortress, hardened by decades of adversarial auditing. Every major exploit campaign since 1999? Bounced off it. So did yours. Five million automated tests missed that flaw. Static analyzers, fuzzing pipelines, CVE scanners, annual security audits. All of them.