Anthropic says GLM-5.3 gives attackers cyber capabilities with weak safeguards

Anthropic reports that Zhipu AI's GLM-5.3 can autonomously build end-to-end cyber exploits and is released without meaningful safeguards against misuse.

In its simulated tests, attackers bypassed the model's safeguards 64% to 100% of the time using simple techniques, while the same attacks failed against safeguarded Claude models.

Anthropic also cites an NIST CAISI assessment calling GLM-5.3 the most cyber-capable open-weight model released to date.