CVE-2025-10531 Mitigation bypass in the Web Compatibility: Tooling component

Description

Mitigation bypass in the Web Compatibility: Tooling component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.

Affected products and versions

Product	Affected versions	Fixed in
Firefox 143	earliest → < 143	143
Thunderbird 143	earliest → < 143	143

Other CVEs of Firefox

The 2221 CVEs of Firefox →

CVE-2026-120572 Incorrect boundary conditions in the Layout: Block and Inline component 8.8 High CVE-2026-118027 Frame poisoning in the Layout component 9.1 Critical CVE-2026-118025 Other issue in the SVG component 8.8 High CVE-2026-118024 Use-after-free in the Graphics: Text component 8.8 High