Vulnerability Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
CVSS Score
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 150.0 |
| Mozilla | Thunderbird | >= 140.0, < 140.10.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2025067Permissions 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
FAQ
What is CVE-2026-6771?
CVE-2026-6771 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
How severe is CVE-2026-6771?
CVE-2026-6771 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-6771?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.