CVE-2025-6425

Details

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 affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

Affected Packages

Firefox

Ubuntu 14.04 LTSUbuntu 16.04 LTSUbuntu 18.04 LTSUbuntu 20.04 LTSUbuntu 22.04 LTS

Fixed in:

140

Mozilla Firefox

Windows 10 (1507)Windows 10 (1607) / Server 2016Windows 10 (1809) / Server 2019Windows 10 (1903)Windows 10 (1909)

Fixed in:

140

Mozilla Firefox ESR

Windows 10 (1507)Windows 10 (1607) / Server 2016Windows 10 (1809) / Server 2019Windows 10 (1903)Windows 10 (1909)

Fixed in:

115.25

Mozilla Firefox ESR

Windows 10 (1507)Windows 10 (1607) / Server 2016Windows 10 (1809) / Server 2019Windows 10 (1903)Windows 10 (1909)

Fixed in:

128.12

Firefox ESR

macOS 14macOS 15macOS 26

Fixed in:

115.25

Firefox ESR

macOS 14macOS 15macOS 26

Fixed in:

128.12

References

WEBhttps://bugzilla.mozilla.org/show_bug.cgi?id=1717672 WEBhttps://lists.debian.org/debian-lts-announce/2025/06/msg00029.html WEBhttps://lists.debian.org/debian-lts-announce/2025/07/msg00002.html ADVISORYhttps://www.cve.org/CVERecord?id=CVE-2025-6425 WEBhttps://www.mozilla.org/security/advisories/mfsa2025-51/WEBhttps://www.mozilla.org/security/advisories/mfsa2025-52/WEBhttps://www.mozilla.org/security/advisories/mfsa2025-53/WEBhttps://www.mozilla.org/security/advisories/mfsa2025-54/WEBhttps://www.mozilla.org/security/advisories/mfsa2025-55/

CVE-2025-6425

Details

Affected Packages

References

CVSS Analysis

Ecosystems(28)

Timeline