Vulnerability Details CVE-2026-100818
Sandbox escape due to use-after-free in the Widget: Gtk component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 18.3%
CVSS Severity
CVSS v3 Score 9.6
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2069399
- https://www.mozilla.org/security/advisories/mfsa2026-100/
- https://www.mozilla.org/security/advisories/mfsa2026-101/
- https://www.mozilla.org/security/advisories/mfsa2026-102/
- https://www.mozilla.org/security/advisories/mfsa2026-103/
- https://www.mozilla.org/security/advisories/mfsa2026-97/
- https://www.mozilla.org/security/advisories/mfsa2026-99/