Epoch AI: open-weight GLM 5.3 exploited the patch gap to hack 6 Firefox releases at ~$1,000 each
rohanpaul_ai · x · 2026-11-02
Epoch AI researchers found that Z.ai's open-weight GLM 5.3 can turn unshipped Firefox security fixes into working exploits across 6 consecutive releases, exploiting the "patch gap" between a fix being published and reaching users.
- The fixes sit in public code disguised as routine changes; GLM 5.3 picked out the real patches and built full exploit chains with zero refusals
- The resulting webpage exfiltrated a visitor's local file with no further clicks, with a route to stored passwords and cookies
- Setup cost over $100K, but each additional Firefox compromise cost only $1,000, fastest in 12 hours
- Every hack also chained a previously unknown Firefox bug the model found itself; Mozilla patched it Oct 27
- The same approach failed against Chrome even after $100K
Related event: Open-source GLM 5.3 Exploits Patch Gaps to Break Six Firefox Versions(2 posts)→
More from Models
- A4 print-ready PDF stress test: only Claude, Gemini and Mistral pass out of 10 AI models — gerardsans · 2026-11-02
- Discounted API relay stations lack prompt caching, making long sessions pricier — uneatenbreakfast · 2026-11-02
- Google open-sources EmbeddingGemma 2: on-device multimodal search across photos, audio, docs — bigaiguy · 2026-11-02
- Anthropic's server-side rule reignites the case for owning open models over renting AI — alex_verem · 2026-11-02
- SemiAnalysis: safety classifiers sandbag scores of Opus 5.5 and GPT-6 Astra — morqon · 2026-11-02
- Liquid AI's 1.7B LFM3 becomes first local model to nail live fixtures lookup on a MacBook — NielsRogge · 2026-11-02