CVE-2009-1306: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 1.3% chance of exploitation in the next 30 days.

The jar: URI implementation in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey does not follow the Content-Disposition header of the inner URI, which allows remote attackers to conduct cross-site scripting (XSS) attacks and possibly other attacks via an uploaded .jar file with a "Content-Disposition: attachment" designation.

Affected products

• Mozilla Firefox: up to and including 3.0.8; version 0.1 only; version 0.2 only; version 0.3 only; version 0.4 only; version 0.5 only; …
• Mozilla Seamonkey: any version
• Mozilla Thunderbird: any version

Published 2009-04-22. Last modified 2026-06-16.