AI Reports · Anthropic · 2026-09-29 · Blog / commentary
GLM-5.3 and the spread of advanced cyber capabilities
Zhipu AI's GLM-5.3 can autonomously build end-to-end cyber exploits and, unlike other frontier models, was released without meaningful safeguards against misuse. In Anthropic's simulated tests, simple techniques bypassed its safeguards 64% to 100% of the time, while the same attacks did not succeed against safeguarded Claude models. NIST's Center for AI Standards and Innovation (CAISI) independently called it 'the most cyber-capable open-weight model released to date.'