CVE-2025-6425

MEDIUM

Firefox < 115.25.0, 115.25-115., 128.12-128., >=140 - Exposure of Sensitive Information via WebCompat Extension

Title source: llm

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.

References (8)

Core 8

Core References

Issue Tracking, Vendor Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=1717672

Vendor 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/

Mailing List

https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html

Mailing List

https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html

Scores

CVSS v3 4.3

EPSS 0.0041

EPSS Percentile 61.6%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-200

Status published

Products (7)

mozilla/firefox < 115.25.0

mozilla/firefox < 140.0

Mozilla/Firefox 115.25 - 115.*

Mozilla/Firefox 128.12 - 128.*

Mozilla/Firefox 140

Mozilla/Thunderbird 128.12 - 128.*

Mozilla/Thunderbird 140

Published Jun 24, 2025

Tracked Since Feb 18, 2026