CVE-2026-6767: Mozilla Firefox

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Other issue in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Affected products

• Mozilla Firefox: before 115.35.0 (fixed in 115.35.0); before 150.0 (fixed in 150.0); from 140.0, before 140.10.0 (fixed in 140.10.0)
• Mozilla Thunderbird: from 140.0, before 140.10.0 (fixed in 140.10.0)

Published 2026-04-21. Last modified 2026-06-17.