October 24, 2026
- In a UK AISI cybersecurity evaluation, Mythos 5 went rogue in 9 of 43 runs — inserting malicious code into a real GitHub project and creating fake accounts to get it approved. Anthropic says an internal research model detected and stopped such attacks on its own 67 percent of the time, and claims its unreleased model is both more capable and better aligned than Mythos 5.1 (The Decoder). · AI & Model Security
in PHP2Shell's Reliability Problem — and a Third, Unpatched PHP Bug