Improper Certificate Validation in Microsoft Windows and Windows Server - CVE-2026-83926
Published: October 14, 2026
Vulnerability identifier: #VU155069
CSH Severity: Low
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83926
CWE-ID: CWE-295
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to bypass Windows biometric authentication.
The vulnerability exists due to improper certificate validation in Windows Hello when determining whether a biometric device is trusted. A local privileged user can use a malicious biometric device to falsely present biometric data to bypass Windows biometric authentication.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-83926
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7807, 10 1809 10.0.17763.9376, 11 23H2 10.0.22631.7652, 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Windows Server - addressed in versions 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650
Windows Server - addressed in versions 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650