CVE-2012-3978: Mozilla Firefox

Medium severity, CVSS 6.8. EPSS: 2.3% chance of exploitation in the next 30 days.

The nsLocation::CheckURL function in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 does not properly follow the security model of the location object, which allows remote attackers to bypass intended content-loading restrictions or possibly have unspecified other impact via vectors involving chrome code.

Affected products

• Mozilla Firefox: 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; …
• Mozilla Seamonkey: up to and including 2.11; version 2.0 only; version 2.0.1 only; version 2.0.2 only; version 2.0.3 only; version 2.0.4 only; …
• Mozilla Thunderbird: up to and including 14.0; 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 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 2012-08-29. Last modified 2026-06-16.