CVE-2009-1571: Mozilla Firefox

High severity, CVSS 10.0. EPSS: 6.5% chance of exploitation in the next 30 days.

Use-after-free vulnerability in the HTML parser in Mozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, Thunderbird before 3.0.2, and SeaMonkey before 2.0.3 allows remote attackers to execute arbitrary code via unspecified method calls that attempt to access freed objects in low-memory situations.

Affected products

• Mozilla Firefox: version 3.0 only; version 3.0.1 only; version 3.0.2 only; version 3.0.3 only; version 3.0.4 only; version 3.0.5 only; …
• Mozilla Seamonkey: version 1.0 only; version 1.0.1 only; version 1.0.2 only; version 1.0.3 only; version 1.0.4 only; version 1.0.5 only; …

Published 2010-02-22. Last modified 2026-06-16.