CVE-2025-9182: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Denial-of-service due to out-of-memory in the Graphics: WebRender component. This vulnerability was fixed in Firefox 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird 140.2.

Affected products

• Mozilla Firefox: before 140.2.0 (fixed in 140.2.0); before 142.0 (fixed in 142.0)
• Mozilla Thunderbird: before 140.2.0 (fixed in 140.2.0); before 142.0 (fixed in 142.0)

Published 2025-08-19. Last modified 2026-09-30.