CVE-2008-5018: Canonical Ubuntu Linux

High severity, CVSS 10.0. EPSS: 3.8% chance of exploitation in the next 30 days.

The JavaScript engine in Mozilla Firefox 3.x before 3.0.4, Firefox 2.x before 2.0.0.18, Thunderbird 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 allows remote attackers to cause a denial of service (crash) via vectors related to "insufficient class checking" in the Date class.

Affected products

• Canonical Ubuntu Linux: version 6.06 only; version 7.10 only; version 8.04 only; version 8.10 only
• Debian Debian Linux: version 4.0 only
• Mozilla Firefox: from 2.0, before 2.0.0.18 (fixed in 2.0.0.18); from 3.0, before 3.0.4 (fixed in 3.0.4)
• Mozilla Seamonkey: from 1.0, before 1.1.13 (fixed in 1.1.13)
• Mozilla Thunderbird: from 2.0, before 2.0.0.18 (fixed in 2.0.0.18)

Published 2008-11-13. Last modified 2026-06-16.