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.