cbcvebase.
CVE-2026-6771
published 2026-04-21

CVE-2026-6771: Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

Affected

9 ranges
VendorProductVersion rangeFixed in
mozillafirefox< Firefox 150Firefox 150
mozillafirefox< 150.0150.0
mozillafirefox——
mozillafirefox>= 140.0 < 140.10.0140.10.0
mozillafirefox_esr< Firefox ESR 140.10Firefox ESR 140.10
mozillathunderbird< Thunderbird 140.10Thunderbird 140.10
mozillathunderbird< Thunderbird 150Thunderbird 150
mozillathunderbird>= 140.0 < 140.10.0140.10.0
rhel10firefox-flatpak——