CVE-2026-0880: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

Sandbox escape due to integer overflow in the Graphics component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

Affected products

• Mozilla Firefox: before 115.32.0 (fixed in 115.32.0); before 147.0 (fixed in 147.0); from 128.0, before 140.7.0 (fixed in 140.7.0)
• Mozilla Thunderbird: before 140.7.0 (fixed in 140.7.0); before 147.0 (fixed in 147.0)

Published 2026-01-13. Last modified 2026-07-15.