CVE-2025-6427 Affecting firefox package, versions <140.0-1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.32% (25th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-FIREFOX-10498724
  • published25 Jun 2025
  • disclosed24 Jun 2025

Introduced: 24 Jun 2025

CVE-2025-6427  (opens in a new tab)

How to fix?

Upgrade Debian:unstable firefox to version 140.0-1 or higher.

NVD Description

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

An attacker was able to bypass the connect-src directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

CVSS Base Scores

version 3.1