CVE-2025-6425 Affecting firefox-esr package, versions <115.25-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.26% (18th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-FIREFOXESR-17764593
  • published1 Jul 2026
  • disclosed24 Jun 2025

Introduced: 24 Jun 2025

CVE-2025-6425  (opens in a new tab)

How to fix?

Upgrade Chainguard firefox-esr to version 115.25-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream firefox-esr package and not the firefox-esr package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 Base Scores

version 3.1