Epoch AI Report: Open-weight model GLM 5.3 constructs a complete Firefox vulnerability chain in under 48 hours with zero human intervention.

According to researchers at Epoch AI, the open-weight model GLM 5.3 constructed complete vulnerability chains for six Firefox versions released between September 17 and October 26 without any human input. It exploited the security patch window between the public release of patches and user updates. The cost per successful attack API call was approximately $1,000, with the fastest execution taking only 12 hours.