Authentication Bypass by Spoofing in Microsoft Windows and Windows Server - CVE-2026-119959
Published: November 11, 2026
Vulnerability identifier: #VU165378
CSH Severity: Low
CVSS v4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-119959
CWE-ID: CWE-290
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local privileged user to spoof an identity and disclose sensitive information.
The vulnerability exists due to improper access control in Windows Hyper-V when enforcing identity-based access restrictions during local operations. A local privileged user can exploit these restrictions to bypass authentication through spoofing and gain unauthorized access to sensitive information.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-119959
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7846, 10 22H2 10.0.19045.7846, 10 1809 10.0.17763.9487, 11 23H2 10.0.22631.7711, 11 24H2 10.0.26100.9911, 11 24H2 10.0.26100.9974, 11 25H2 10.0.26200.9911, 11 25H2 10.0.26200.9974, 11 26H1 10.0.28000.3501
Windows Server - addressed in versions 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822
Windows Server - addressed in versions 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822