CVE-2026-84128

HighCVSS 8.8

Published: 01/09/2026(UTC)Updated: 03/09/2026(UTC)Translated: 02/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.25%

16th percentile - higher than 16% of all known CVEs

Summary

Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

Risk Assessment

The risk involves potential privilege escalation, which could allow an attacker to gain unauthorized access to browser features.

Recommendation

It is recommended to update to Firefox 155 or Thunderbird 155, which contain the fix.

Other vulnerabilities in Firefox

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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)

Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

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