Description
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Affected products
mozilla: firefox; mozilla: thunderbird
References5
- www.mozilla.org/security/advisories/mfsa2026-46/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-48/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-50/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-51/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=2034754 Permissions Required
Metrics
- CVSS 3.1
-
9.6
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 37 · as of 14 November 2026
- CWE
- CWE-20CWE-119CWE-693
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