CVE-2011-0066: Mozilla Firefox

High severity, CVSS 10.0. EPSS: 4.8% chance of exploitation in the next 30 days.

Use-after-free vulnerability in Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, and SeaMonkey before 2.0.14, allows remote attackers to execute arbitrary code via vectors related to OBJECT's mObserverList.

Affected products

• Mozilla Firefox: version 3.6 only; version 3.6.2 only; version 3.6.3 only; version 3.6.4 only; version 3.6.6 only; version 3.6.7 only; …
• Mozilla Seamonkey: up to and including 2.0.13; version 1.0 only; version 1.0.1 only; version 1.0.2 only; version 1.0.3 only; version 1.0.4 only; …

Published 2011-05-07. Last modified 2026-06-16.