CVE-2025-6425
The WebCompat WebExtension shipped with Firefox exposed a persistent UUID
- State
- Published
- Severity
- 4.3 Medium
- Published
- Jun 24, 2025
- Updated
- Apr 13, 2026
- Reserved
- Jun 20, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N | CISA-ADP |
Weaknesses
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
Affected Products
| Product | Versions |
|---|---|
FirefoxMozilla |
|
ThunderbirdMozilla |
|
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1717672
- https://www.mozilla.org/security/advisories/mfsa2025-51/
- https://www.mozilla.org/security/advisories/mfsa2025-52/
- https://www.mozilla.org/security/advisories/mfsa2025-53/
- https://www.mozilla.org/security/advisories/mfsa2025-54/
- https://www.mozilla.org/security/advisories/mfsa2025-55/
- https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html
- https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html
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