10a Labs

Anthropic's Claude Opus 5.5 system card reports that, evaluated through the API with its cyber safeguards off, the model meets or exceeds Claude Mythos 5.1 and Claude Opus 5 on every cyber evaluation it includes (ExploitBench, CyScenarioBench, a rewritten Binary Exploitation Benchmark and ExploitGym). Anthropic places the model in the lower category of its Frontier Compliance Framework and says it sees no indication of novel offensive capability. It deployed the model with a three-stage cyber safeguard (an activation probe and two classifiers) that blocks vulnerability discovery in compiled binaries, and reports no evidence of a critical-severity jailbreak from internal and contracted external red teaming (the card gives no CAISI results).