CVE-2025-14331: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.2% chance of exploitation in the next 30 days.

Same-origin policy bypass in the Request Handling component. This vulnerability was fixed in Firefox 146, Firefox ESR 115.31, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.

Affected products

• Mozilla Firefox: before 115.31.0 (fixed in 115.31.0); before 146.0 (fixed in 146.0); from 116.0, before 140.6.0 (fixed in 140.6.0)
• Mozilla Thunderbird: before 140.6.0 (fixed in 140.6.0); before 146.0 (fixed in 146.0)

Published 2025-12-09. Last modified 2026-10-07.