Firefox CSS Parsing Use-After-Free (before 149, ESR <115.34/140.9)
CVE-2026-4691 Published on March 24, 2026
Use-after-free in the CSS Parsing and Computation component
Use-after-free in the CSS Parsing and Computation component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
Products Associated with CVE-2026-4691
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Affected Versions
Mozilla Firefox:- Version unspecified and below 149 is affected.
- Version unspecified and below 115.34 is affected.
- Version unspecified and below 140.9 is affected.
- Version unspecified and below 149 is affected.
- Version unspecified and below 140.9 is affected.