CVE-2009-3986: Mozilla Firefox

High severity, CVSS 7.6. EPSS: 3.7% chance of exploitation in the next 30 days.

Mozilla Firefox before 3.0.16 and 3.5.x before 3.5.6, and SeaMonkey before 2.0.1, allows remote attackers to execute arbitrary JavaScript with chrome privileges by leveraging a reference to a chrome window from a content window, related to the window.opener property.

Affected products

• Mozilla Firefox: up to and including 3.0.15; version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; …
• Mozilla Seamonkey: up to and including 2.0; version 1.0 only; version 1.0.1 only; version 1.0.2 only; version 1.0.3 only; version 1.0.4 only; …

Published 2009-12-17. Last modified 2026-06-16.