Reliance on Untrusted Inputs in a Security Decision in Microsoft Windows and Windows Server - CVE-2026-0390
Published: April 15, 2026
Vulnerability identifier: #VU126185
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-0390
CWE-ID: CWE-807
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to compromise the target system.
The vulnerability exists due to reliance on untrusted input for a security decision in UEFI Secure Boot. A local administrator can bypass authentication feature and cause impersonation.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-0390
Install updates from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7184, 10 22H2 10.0.19045.7184, 10 1607 10.0.14393.9060, 10 1809 10.0.17763.8644, 11 26H1 10.0.28000.1836
Windows Server - addressed in versions 2012 R2 6.3.9600.23132, 2016 10.0.14393.9060, 2019 10.0.17763.8644, 2022 10.0.20348.5020
Windows Server - addressed in versions 2012 R2 6.3.9600.23132, 2016 10.0.14393.9060, 2019 10.0.17763.8644, 2022 10.0.20348.5020