CVE-2025-6425
4.3
MEDIUM
CVSS 3.1
EPSS 0.41%
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.
How to fix CVE-2025-6425
To remediate CVE-2025-6425, upgrade the affected package to a fixed version below.
- —upgrade to 128.12.0esr-1~deb11u1 or later
- —upgrade to 1:128.12.0esr-1~deb11u1 or later
Is CVE-2025-6425 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 128.12.0esr-1~deb11u1
- from 0, < 1:128.12.0esr-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N |