Anthropic raises alarm over Chinese GLM-5.3 model’s elite hacking ability - South China Morning Post

Chong Ming LeePublished: 8:00pm, 30 Sep 2026The US artificial intelligence giant Anthropic has warned of the potential danger posed by Chinese firm Z.ai’s GLM-5.3, with the open-weight model showing a troubling mix of powerful hacking abilities but weak safety constraints.

GLM-5.3 almost matches Anthropic’s most advanced model in terms of its cyber capabilities, but has far weaker safeguards, meaning there is greater potential for the model to be co-opted by bad actors, according to the San Francisco-based firm.

In a report released on Tuesday, Anthropic said it had tested GLM-5.3’s ability to build end-to-end cyber exploits. The Chinese model successfully completed 50 out of 410 exploit attempts, compared with 56 for Claude Mythos Preview, a frontier Anthropic model that can only be used by vetted users.