Vulnerability Description
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.39.0 |
| Mozilla | Thunderbird | < 140.14.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2054416Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-74/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-75/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-76/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-77/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-78/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-79/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-80/Vendor Advisory
FAQ
What is CVE-2026-74939?
CVE-2026-74939 is a vulnerability with a CVSS score of 8.8 (HIGH). Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and ...
How severe is CVE-2026-74939?
CVE-2026-74939 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-74939?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.