CVE-2026-109780

critical

Description

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

References

https://www.mozilla.org/security/advisories/mfsa2026-109/

https://www.mozilla.org/security/advisories/mfsa2026-106/

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-98540

https://bugzilla.mozilla.org/show_bug.cgi?id=2072775

Details

Source: Mitre, NVD

Published: 2026-10-13

Updated: 2026-10-13

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00198