Anthropic's Claude Fable 5.2 Beats GPT-6 Cyber in Multi-Stage Cyberattack Benchmark
Nov 10, 2026
Artificial Intelligence / Application Security
Anthropic on Monday released Claude Fable 5.2 and Claude Mythos 5.2 models, which it said exhibit improvements in coding, reasoning, and vision. During pre-release training, the large language models (LLMs) helped its engineers "complete otherwise-infeasible software migrations, designed three working electronic devices from scratch, solved two open problems in the physics of black holes, made substantial progress on robotics evaluations, and formalized the proof of Fermat’s Last Theorem in 30 hours." The artificial intelligence (AI) company said high-stakes risks arising from misalignment remain low, and claimed the models matched or performed better than Claude Opus 5.5, Claude Sonnet 5.5, and Claude Mythos 5.1 on most alignment measures, resistance to misuse, honesty, and factuality. "It was roughly an order of magnitude less likely than Opus 5.5 and Sonnet 5.5 to publish harmful content to public package registries without encouragement, though it still did...