CVE-2026-6771

critical · 9.8

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

9.8

CVSS

0.3%

EPSS (exploit prob.)

24th

EPSS percentile

2026-04-21

Published

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

Weaknesses

CWE-288

Affected products

Vendor	Product	Affected versions
mozilla	firefox	< 150.0
mozilla	firefox	>= 140.0, < 140.10.0
mozilla	thunderbird	>= 140.0, < 140.10.0

Check a specific version with /api/v1/cve/match.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2025067
https://www.mozilla.org/security/advisories/mfsa2026-30/
https://www.mozilla.org/security/advisories/mfsa2026-32/
https://www.mozilla.org/security/advisories/mfsa2026-33/
https://www.mozilla.org/security/advisories/mfsa2026-34/

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-6771