CVE-2012-0463: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 4.2% chance of exploitation in the next 30 days.

The nsWindow implementation in the browser engine in Mozilla Firefox before 3.6.28 and 4.x through 10.0, Firefox ESR 10.x before 10.0.3, Thunderbird before 3.1.20 and 5.0 through 10.0, Thunderbird ESR 10.x before 10.0.3, and SeaMonkey before 2.8 does not check the validity of an instance after event dispatching, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors, as demonstrated by Mobile Firefox on Android.

Affected products

• Mozilla Firefox: up to and including 3.6.27; after 4.0, up to and including 10.0; version 10.0 only; version 10.0.1 only; version 10.0.2 only
• Mozilla Seamonkey: affected versions not specified; version 1.0 only; version 1.0.1 only; version 1.0.2 only; version 1.0.3 only; version 1.0.4 only; …
• Mozilla Thunderbird: from 1.0, up to and including 3.1.19; after 5.0, up to and including 10.0
• Mozilla Thunderbird ESR: version 10.0 only; version 10.0.1 only; version 10.0.2 only

Published 2012-03-14. Last modified 2026-06-16.