CVE-2012-3963: Use-after-free vulnerability in the js::gc::MapAllocToTraceKind function in Mozilla Firefox before 15.0, Fi...

Security readout for executives and security teams

This is an old Mozilla memory-safety flaw that could let a remote attacker run code through unspecified content handled by Firefox, Thunderbird, or SeaMonkey. The business risk is mainly from unsupported legacy browsers or mail clients still present on endpoints or packaged into older systems. Exposure is most plausible where legacy Mozilla clients remain installed, especially pre-15 Firefox or Thunderbird ESR 10.x before 10.0.7. Modern environments are unlikely to be exposed unless old software persists on unmanaged endpoints or legacy images. Treat as a legacy exposure cleanup item with high severity if affected software exists. Prioritize verification on unmanaged endpoints, old Linux distributions, and systems that may still use outdated Mozilla clients. Mitigation focus: Upgrade Firefox to 15.0 or later where still applicable.; Upgrade Firefox ESR 10.x to 10.0.7 or later.; Upgrade Thunderbird to 15.0 or Thunderbird ESR 10.0.7 or later..

Prepared

Jun 28, 2026, 00:52 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.