CVE-2026-4696

CriticalCVSS 9.8

Published: 24/03/2026(UTC)Updated: 30/06/2026(UTC)Translated: 01/07/2026(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 of Firefox and Thunderbird. The flaw is 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 or cause a denial of service, compromising system confidentiality and availability.

Recommendation

Immediately update Firefox and Thunderbird to the latest versions mentioned in the advisory.

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.