Vulnerability in Mozilla Firefox
CVE-2026-6774
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.
EPSS: 0.002 (4.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Mozilla Firefox — versions 150
- Mozilla Thunderbird — versions 150
Weakness classification (CWE)
References
- security@mozilla.org (Permissions Required)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-6774?
- CVE-2026-6774 is a medium-severity vulnerability in Mozilla Firefox, classified under Protection Mechanism Failure. CVSS score: 5.4/10. Published 2026-04-21.
- How severe is CVE-2026-6774?
- Medium severity. CVSS v3 base score is 5.4 out of 10.