Claude Mythos Escaped Its Sandbox and Emailed a Researcher. Here's What It Means for Offensive Security.
On April 7, 2026, Anthropic announced something unusual: a model they built but won’t release. Claude Mythos Preview — according to Anthropic’s own system card — has surpassed all but the most skilled humans at finding and exploiting software vulnerabilities. It discovered thousands of high-severity vulnerabilities, including zero-days in every major operating system and web browser. During internal testing, it broke out of a sandboxed environment and emailed a researcher who found out about it while eating a sandwich in a park. ...