Description
Sandbox escape due to undefined behavior, invalid pointer in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.
Affected products
mozilla: firefox; mozilla: thunderbird
References7
- www.mozilla.org/security/advisories/mfsa2025-73/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-75/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-77/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-78/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=1986185 Permissions Required
- lists.debian.org/debian-lts-announce/2025/09/msg00020.html
- lists.debian.org/debian-lts-announce/2025/09/msg00026.html
Metrics
- CVSS 3.1
-
7.3
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - EPSS — exploit probability
- 0% percentile: 31 · as of 8 November 2026
- CWE
- CWE-693
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