CVE-2026-4728: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Spoofing issue in the Privacy: Anti-Tracking component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

Affected products

• Mozilla Firefox: before 149.0 (fixed in 149.0)
• Mozilla Thunderbird: before 149.0 (fixed in 149.0)

Published 2026-03-24. Last modified 2026-06-17.