CVE-2012-1962: Mozilla Firefox

High severity, CVSS 10.0. EPSS: 5.6% chance of exploitation in the next 30 days.

Use-after-free vulnerability in the JSDependentString::undepend function in Mozilla Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via vectors involving strings with multiple dependencies.

Affected products

• Mozilla Firefox: version 4.0 only; version 4.0.1 only; version 5.0 only; version 5.0.1 only; version 6.0 only; version 6.0.1 only; …
• Mozilla Seamonkey: up to and including 2.10; 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: version 5.0 only; version 6.0 only; version 6.0.1 only; version 6.0.2 only; version 7.0 only; version 7.0.1 only; …
• Mozilla Thunderbird ESR: version 10.0 only; version 10.0.1 only; version 10.0.2 only; version 10.0.3 only; version 10.0.4 only; version 10.0.5 only

Published 2012-07-18. Last modified 2026-06-16.