CVE-2025-1014: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Certificate length was not properly checked when added to a certificate store. In practice only trusted data was processed. 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: from 128.0.1, before 128.7.0 (fixed in 128.7.0); from 131.0, before 135.0 (fixed in 135.0)

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