CVE-2009-2462: Mozilla Firefox

High severity, CVSS 10.0. EPSS: 5.4% chance of exploitation in the next 30 days.

The browser engine in Mozilla Firefox before 3.0.12 and Thunderbird allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to (1) the frame chain and synchronous events, (2) a SetMayHaveFrame assertion and nsCSSFrameConstructor::CreateFloatingLetterFrame, (3) nsCSSFrameConstructor::ConstructFrame, (4) the child list and initial reflow, (5) GetLastSpecialSibling, (6) nsFrameManager::GetPrimaryFrameFor and MathML, (7) nsFrame::GetBoxAscent, (8) nsCSSFrameConstructor::AdjustParentFrame, (9) nsDOMOfflineResourceList, and (10) nsContentUtils::ComparePosition.

Affected products

• Mozilla Firefox: version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; version 0.6 only; …
• Mozilla Thunderbird: version 2.0.0.0 only; version 2.0.0.1 only; version 2.0.0.2 only; version 2.0.0.3 only; version 2.0.0.4 only; version 2.0.0.5 only; …

Published 2009-07-22. Last modified 2026-06-16.