CVE-2025-11712 Affecting firefox-esr package, versions <140.4-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-17765228
  • published1 Jul 2026
  • disclosed14 Oct 2025

Introduced: 14 Oct 2025

CVE-2025-11712  (opens in a new tab)

How to fix?

Upgrade Chainguard firefox-esr to version 140.4-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.

A malicious page could have used the type attribute of an OBJECT tag to override the default browser behavior when encountering a web resource served without a content-type. This could have contributed to an XSS on a site that unsafely serves files without a content-type header. This vulnerability was fixed in Firefox 144, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

CVSS Base Scores

version 3.1