Permissions, Privileges, and Access Controls in Windows Server and Windows - CVE-2026-20817
Published: January 13, 2026 / Updated: February 27, 2026
Vulnerability identifier: #VU121246
CSH Severity: Low
CVSS v4.0: 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/E:P/U:Clear
CVE-ID: CVE-2026-20817
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vendor: Microsoft
Affected software:
Windows Server
Windows
Windows Server
Windows
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to application does not properly impose security restrictions in Windows Error Reporting Service, which leads to security restrictions bypass and privilege escalation.
How to mitigate CVE-2026-20817
Install updates from vendor's website.