CVE-2006-1731: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 1.8% chance of exploitation in the next 30 days.

Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 returns the Object class prototype instead of the global window object when (1) .valueOf.call or (2) .valueOf.apply are called without any arguments, which allows remote attackers to conduct cross-site scripting (XSS) attacks.

Affected products

• Mozilla Firefox: up to and including 1.0.7; 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 Mozilla Suite: up to and including 1.7.12; version 1.7.6 only; version 1.7.7 only; version 1.7.8 only; version 1.7.10 only; version 1.7.11 only
• Mozilla Seamonkey: up to and including 1.0; version 1.0 only
• Mozilla Thunderbird: up to and including 1.0.7; version 1.0 only; version 1.0.1 only; version 1.0.2 only; version 1.0.3 only; version 1.0.4 only; …

Published 2006-04-14. Last modified 2026-06-16.