Vulnerability in Mozilla Firefox
CVE-2026-4691
Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
EPSS: 0.000 (12.1th percentile) — read the EPSS interpretation.
Affected products
- Mozilla Firefox — versions 115.34, 140.9, 149
- Mozilla Thunderbird — versions 140.9, 149