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CVE-2026-4711 - Vulnerability Analysis

CriticalCVSS: 9.8

Last Updated: March 24, 2026

Mozilla Firefox - Use After Free

Published: March 24, 2026Updated: March 24, 2026Remote Exploitable

Overview

Mozilla Firefox < 149 and Firefox ESR < 140.9 contain a use-after-free vulnerability caused by improper memory management in the Widget: Cocoa component, letting attackers potentially execute arbitrary code, exploit requires crafted input.

Severity & Score

Severity: Critical

CVSS Score: 9.8

Impact

Attackers can execute arbitrary code remotely, potentially leading to full system compromise.

Mitigation

Update to Firefox 149 and Firefox ESR 140.9 or later.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2017002
https://www.mozilla.org/security/advisories/mfsa2026-20/
https://www.mozilla.org/security/advisories/mfsa2026-22/

Related Resources

Vulnerability Intelligence Dashboard
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Details

CVE ID: CVE-2026-4711
Severity: Critical
CVSS Score: 9.8
Type: use_after_free
Status: confirmed

CWE

CWE-416

CVSS Metrics

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H