CVE-2006-6503: Canonical Ubuntu Linux

Medium severity, CVSS 6.8. EPSS: 4.2% chance of exploitation in the next 30 days.

Mozilla Firefox 2.x before 2.0.0.1, 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7 allows remote attackers to bypass cross-site scripting (XSS) protection by changing the src attribute of an IMG element to a javascript: URI.

Affected products

• Canonical Ubuntu Linux: version 5.10 only; version 6.06 only; version 6.10 only
• Debian Debian Linux: version 3.1 only; version 4.0 only
• Mozilla Firefox: from 1.5, before 1.5.0.9 (fixed in 1.5.0.9); from 2.0, before 2.0.0.1 (fixed in 2.0.0.1)
• Mozilla Seamonkey: before 1.0.7 (fixed in 1.0.7)
• Mozilla Thunderbird: before 1.5.0.9 (fixed in 1.5.0.9)

Published 2006-12-20. Last modified 2026-06-16.