CVE-2026-92021

HighCVSS 8.8

Published: 15/09/2026(UTC)Updated: 20/09/2026(UTC)Translated: 16/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.30%

23th percentile - higher than 23% of all known CVEs

Summary

Use-after-free vulnerability in the JavaScript Engine: JIT component. Fixed in Firefox ESR 140.16 and Thunderbird 140.16.

Risk Assessment

May lead to malfunction of the JavaScript engine and potentially code execution.

Recommendation

Update Firefox ESR or Thunderbird to version 140.16 or later.

Other vulnerabilities in Firefox

See all

CVE-2026-92079Critical
Mitigation bypass vulnerability in the Widget: Win32 component. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92075Critical
Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92071Critical
Sandbox escape vulnerability due to incorrect boundary conditions in the Widget: Win32 component. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92066Critical
Sandbox escape in the Profile Backup component of Firefox and Thunderbird. This vulnerability was fixed in Firefox 156 and Thunderbird 156.
CVE-2026-92061Critical
Incorrect boundary conditions in the Security: Process Sandboxing component. Fixed in Firefox 156 and Thunderbird 156.
CVE-2026-92057Critical
Mitigation bypass vulnerability in the Enterprise Policies component. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92051Critical
Spoofing issue due to invalid pointer in the Graphics component. Fixed in Firefox 156 and Thunderbird 156.
CVE-2026-92048Critical
Sandbox escape vulnerability due to incorrect boundary conditions in the Widget: Win32 component. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92045Critical
Sandbox escape vulnerability due to incorrect boundary conditions in the WebRTC component. It was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
CVE-2026-92037Critical
Incorrect boundary conditions in the DOM: Animation component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.

Original NVD description (English source)

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox ESR 140.16 and Thunderbird 140.16.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS