CVE-2026-109780

Mitigation bypass in the DOM: Core & HTML component

State: Published
Severity: 9.8 Critical
Published: Oct 13, 2026
Updated: Oct 26, 2026
Reserved: Oct 13, 2026

Description

Mitigation bypass in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-693 Protection Mechanism Failure

Affected Products

Product	Versions
FirefoxMozilla	158 and laterNot affected
ThunderbirdMozilla	158 and laterNot affected

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2072775
https://www.mozilla.org/security/advisories/mfsa2026-106/
https://www.mozilla.org/security/advisories/mfsa2026-109/

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.