CVE-2025-1013: Mozilla Firefox

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

A race condition could have led to private browsing tabs being opened in normal browsing windows. This could have resulted in a potential privacy leak. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

Affected products

• Mozilla Firefox: before 128.7.0 (fixed in 128.7.0); before 135.0 (fixed in 135.0)
• Mozilla Thunderbird: before 128.7.0 (fixed in 128.7.0); from 129.0, before 135.0 (fixed in 135.0)

Published 2025-02-04. Last modified 2026-10-05.