Quoting Anthropic Frontier Red Team

Anthropic Frontier Red Team evaluated multiple models on 100 randomly sampled tasks from an internal Binary Exploitation benchmark; GLM-5.3 achieved full control-flow hijack in 4% of trials, and Claude Mythos Preview in 6%. Earlier models like Claude Opus 4.6 and GLM-5.2 had no successes, and the author argues a meaningful threshold has been crossed.