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VULNERABILITIES

CVE-2026-4691 Details

Description

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:9.8 CRITICALVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA: redhat-SADPCVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URLSource(s)Tag(s)
https://access.redhat.com/errata/RHSA-2026:5930 redhat-SADP
https://access.redhat.com/errata/RHSA-2026:5931 redhat-SADP
https://access.redhat.com/errata/RHSA-2026:5932 redhat-SADP
https://access.redhat.com/errata/RHSA-2026:6188 redhat-SADP
https://access.redhat.com/errata/RHSA-2026:6342 redhat-SADP

see all 34 references

Weakness Enumeration

CWE-IDCWE NameSource
CWE-416Use After Free[email protected]
CWE-416Use After FreeCISA-ADP
CWE-825Expired Pointer Dereferenceredhat-SADP

Affected Products

ProductVersions
mozilla firefox
< 115.34.0
< 149.0
>= 128.0, < 140.9.0

CPE

  • cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*

Remediation

  • No remediation found in references.

Change History

9 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-4691
NVD Published Date:
Mar 24, 2026
NVD Last Modified:
Jul 15, 2026
Source:
[email protected]
CVE-2026-4691 Details - Not Deferred