CVE-2008-5510: Canonical Ubuntu Linux

Medium severity, CVSS 5.0. EPSS: 2.2% chance of exploitation in the next 30 days.

The CSS parser in Mozilla Firefox 3.x before 3.0.5 and 2.x before 2.0.0.19, Thunderbird 2.x before 2.0.0.19, and SeaMonkey 1.x before 1.1.14 ignores the '\0' escaped null character, which might allow remote attackers to bypass protection mechanisms such as sanitization routines.

Affected products

• Canonical Ubuntu Linux: version 7.10 only; version 8.04 only; version 8.10 only
• Debian Debian Linux: version 4.0 only; version 5.0 only
• Mozilla Firefox: from 2.0, before 2.0.0.19 (fixed in 2.0.0.19); from 3.0, before 3.0.5 (fixed in 3.0.5)
• Mozilla Seamonkey: from 1.0, before 1.1.14 (fixed in 1.1.14)
• Mozilla Thunderbird: from 2.0, before 2.0.0.19 (fixed in 2.0.0.19)

Published 2008-12-17. Last modified 2026-06-16.