CVE-2009-4129: Mozilla Firefox

Medium severity, CVSS 5.8. EPSS: 0.8% chance of exploitation in the next 30 days.

Race condition in Mozilla Firefox allows remote attackers to produce a JavaScript message with a spoofed domain association by writing the message in between the document request and document load for a web page in a different domain.

Affected products

• Mozilla Firefox: any version

Published 2009-12-14. Last modified 2026-06-16.