CVE-2010-3769: Mozilla Firefox

High severity, CVSS 9.3. EPSS: 4.6% chance of exploitation in the next 30 days.

The line-breaking implementation in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbird before 3.0.11 and 3.1.x before 3.1.7, and SeaMonkey before 2.0.11 on Windows does not properly handle long strings, which allows remote attackers to execute arbitrary code via a crafted document.write call that triggers a buffer over-read.

Affected products

• Mozilla Firefox: up to and including 3.5.15; 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 2.0.10; 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: up to and including 3.0.10; version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; …

Published 2010-12-10. Last modified 2026-06-16.