Incorrect Implementation of Authentication Algorithm in Microsoft Windows and Windows Server - CVE-2026-83906
Published: October 14, 2026
Vulnerability identifier: #VU155049
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83906
CWE-ID: CWE-303
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information through spoofing.
The vulnerability exists due to incorrect implementation of an authentication algorithm in Windows Shell when performing authentication over a network. A remote attacker can exploit the incorrectly implemented authentication algorithm to disclose sensitive information through spoofing.
Exploitation requires user interaction.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-83906
Install security update from vendor's website.
Microsoft Windows - addressed in versions 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 - update to 2025 10.0.26100.33650
Windows Server - update to 2025 10.0.26100.33650