CVE-2026-4696

CriticalCVSS 9.8

Published: 24/03/2026(UTC)Updated: 15/07/2026(UTC)Translated: 16/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.48%

38th percentile - higher than 38% of all known CVEs

Summary

A use-after-free vulnerability was found in the Layout: Text and Fonts component. This flaw was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Risk Assessment

An attacker could exploit this vulnerability to execute arbitrary code remotely or cause a denial of service, posing a serious risk to confidentiality and system availability.

Recommendation

Immediately update Firefox to version 149 or later (or the appropriate ESR version) and Thunderbird to version 149 or 140.9.

Original NVD description (English source)

Use-after-free in the Layout: Text and Fonts component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.