# Open-weight model GLM 5.3 built Firefox exploit chains with no human input in under 48 hours

> Original title: Open-weight model GLM 5.3 built full Firefox exploit chains with zero human input in under 48 hours

- Source: The Decoder
- Published: 2026-10-30T12:22:18.000Z
- Bad Influence: https://badinfluence.news/items/nnuq9rdaqpnrflsu9bo8zcvm9
- Original: https://the-decoder.com/open-weight-model-glm-5-3-built-full-firefox-exploit-chains-with-zero-human-input-in-under-48-hours/

## Summary

Epoch AI researchers found that the open-weight model GLM 5.3 exploited the time gap between Firefox security patch publication and user delivery. Across six Firefox versions released between September 17 and October 26, the model built working exploit chains at roughly $1,000 in API fees per attack. Mozilla patched the underlying vulnerability in Firefox 159.0, released October 27, 2026.