CVE-2026-6771

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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.

9.8 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2025067 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-30/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-32/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-33/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-34/ Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
History

22 Apr 2026, 16:06

Type Values Removed Values Added
First Time Mozilla
Mozilla firefox
Mozilla thunderbird
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
References () https://bugzilla.mozilla.org/show_bug.cgi?id=2025067 - () https://bugzilla.mozilla.org/show_bug.cgi?id=2025067 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2026-30/ - () https://www.mozilla.org/security/advisories/mfsa2026-30/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-32/ - () https://www.mozilla.org/security/advisories/mfsa2026-32/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-33/ - () https://www.mozilla.org/security/advisories/mfsa2026-33/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-34/ - () https://www.mozilla.org/security/advisories/mfsa2026-34/ - Vendor Advisory

22 Apr 2026, 00:16

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2026-33/ -
  • () https://www.mozilla.org/security/advisories/mfsa2026-34/ -
Summary (en) Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10. (en) Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

21 Apr 2026, 20:17

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.8
CWE CWE-288

21 Apr 2026, 13:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-04-21 13:16

Updated : 2026-04-22 16:06

NVD link : CVE-2026-6771

Mitre link : CVE-2026-6771

CVE.ORG link : CVE-2026-6771

JSON object : View

Products Affected

mozilla

  • thunderbird
  • firefox
CWE
CWE-288

Authentication Bypass Using an Alternate Path or Channel