CVE-2026-92039: Mozilla Firefox

Medium severity, CVSS 6.3. EPSS: 0.2% chance of exploitation in the next 30 days.

Mitigation bypass in the DOM: Notifications component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

Affected products

• Mozilla Firefox: before 153.3.0 (fixed in 153.3.0); from 154.0.0, before 156.0.0 (fixed in 156.0.0)
• Mozilla Thunderbird: before 153.3.0 (fixed in 153.3.0); from 154.0, before 156.0 (fixed in 156.0)

Published 2026-09-15. Last modified 2026-10-05.