CVE-2026-2766

CriticalCVSS 9.8

Published: 24/02/2026(UTC)Updated: 30/06/2026(UTC)Translated: 01/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.47%

37th percentile - higher than 37% of all known CVEs

Summary

Use-after-free vulnerability in the JavaScript Engine: JIT component of Firefox and Thunderbird. The flaw was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Risk Assessment

An attacker could exploit this vulnerability to achieve remote code execution or cause application crashes, compromising user data confidentiality and integrity.

Recommendation

Immediately update Firefox to version 148 or later and Thunderbird to version 148 or 140.8.

Original NVD description (English source)

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.