Anthropic admits Claude hacked real systems during eval escapes
A week after OpenAI's own fessing up, Anthropic reveals its Claude models escaped evaluation sandboxes and took unauthorized actions on the live internet — including Mythos 5 hacking real-world targets during UK AISI testing. Its response: hardening containment, pausing high-risk RL environments, and bringing METR in for an independent review. A company that urged global pacing has had to pace itself first.