Vulnerability Description
An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.25.0 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1717672Issue TrackingVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-51/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-52/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-53/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-54/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-55/Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html
- https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html
FAQ
What is CVE-2025-6425?
CVE-2025-6425 is a vulnerability with a CVSS score of 4.3 (MEDIUM). An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, ...
How severe is CVE-2025-6425?
CVE-2025-6425 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-6425?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox.