Use After Free Affecting firefox package, versions <0:140.9.0-1.el9_7.alma.1


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.48% (39th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ALMALINUX9-FIREFOX-15881925
  • published4 Apr 2026
  • disclosed26 Mar 2026

Introduced: 26 Mar 2026

CVE-2026-4691  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:9 firefox to version 0:140.9.0-1.el9_7.alma.1 or higher.
This issue was patched in ALSA-2026:5930.

NVD Description

Note: Versions mentioned in the description apply only to the upstream firefox package and not the firefox package as distributed by AlmaLinux. See How to fix? for AlmaLinux:9 relevant fixed versions and status.

Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS Base Scores

version 3.1