CVE-2026-100804

Sandbox escape due to use-after-free in the Preferences: Backend component

State: Published
Severity: 9.6 Critical
Published: Sep 29, 2026
Updated: Sep 30, 2026
Reserved: Sep 26, 2026

Description

Sandbox escape due to use-after-free in the Preferences: Backend component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

Scores

CVSS	Score	Vector	Source
3.1	9.6 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-416 Use After Free

Affected Products

Product	Versions
ThunderbirdMozilla	157 and laterNot affected
FirefoxMozilla	157 and laterNot affected

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2058647
https://www.mozilla.org/security/advisories/mfsa2026-101/
https://www.mozilla.org/security/advisories/mfsa2026-97/

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