Insufficient Granularity of Access Control in Microsoft Windows and Windows Server - CVE-2026-50405

Vulnerability identifier: #VU138028

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-50405

CWE-ID: CWE-1220

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to insufficient granularity of access control in Windows Filtering Platform (WFP) when handling local access to filtering platform resources. A local user can leverage the access control weakness to escalate privileges.

Successful exploitation could result in SYSTEM privileges.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7548, 10 22H2 10.0.19045.7548, 10 1607 10.0.14393.9339, 10 1809 10.0.17763.9020, 11 24H2 10.0.26100.8875, 11 25H2 10.0.26200.8875, 11 26H1 10.0.28000.2269, 11 26H1 10.0.28000.2525
Windows Server - addressed in versions 2012 R2 6.3.9600.23291, 2012 6.2.9200.26226, 2016 10.0.14393.9339, 2019 10.0.17763.9020, 2022 10.0.20348.5386, 2025 10.0.26100.33158

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-50405

• Multiple vulnerabilities in Microsoft Windows