Description
Mitigation bypass in the Web Compatibility: Tooling component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.
Affected products
mozilla: firefox; mozilla: thunderbird
References3
- www.mozilla.org/security/advisories/mfsa2025-73/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-77/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1978453 Permissions Required
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 20 · as of 8 November 2026
- CWE
- CWE-288
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