CVE-2009-3981: Mozilla Firefox

High severity, CVSS 9.3. EPSS: 3.7% chance of exploitation in the next 30 days.

Unspecified vulnerability in the browser engine in Mozilla Firefox before 3.0.16, SeaMonkey before 2.0.1, and Thunderbird allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.

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; …
• Mozilla Thunderbird: any version

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