Edition October 31, 2026

GLM 5.3 built Firefox exploit chains without human input

Epoch AI reports that an open-weight model exploited the delay between public fixes and Firefox updates.

The researchers report successful attacks on 6 Firefox versions, costing roughly $1,000 in API fees per success. Mozilla addressed the disclosed flaw in Firefox 159.0; the team has not established whether comparable attacks still work after that fix. The same approach produced no equivalent Chrome exploit, but the researchers explicitly reject treating this as proof of immunity. Their proposed mitigations are coordinated release of fixes and faster distribution of security updates.

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