CVE-2025-4085 Affecting firefox-esr package, versions <138-r0


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.29% (22nd percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-FIREFOXESR-17764079
  • published1 Jul 2026
  • disclosed29 Apr 2025

Introduced: 29 Apr 2025

CVE-2025-4085  (opens in a new tab)

How to fix?

Upgrade Chainguard firefox-esr to version 138-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 with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

CVSS Base Scores

version 3.1