Elevation of Privilege Vulnerability in Windows Win32K by Microsoft
CVE-2026-20870

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Windows Server 2025 (server Core Installation)
Windows 11 Version 25h2
Windows 11 Version 24h2
Windows Server 2025
Vendor
CVE Published:
13 January 2026

What is CVE-2026-20870?

A use after free vulnerability in the Windows Win32K component allows an authorized attacker to gain elevated privileges locally. This can potentially enable unauthorized access to system resources or sensitive information, compromising the integrity and security of the system. Users are recommended to apply updates from the vendor to mitigate this risk.

Affected Version(s)

Windows 11 Version 24H2 ARM64-based Systems 10.0.26100.0 < 10.0.26100.7623

Windows 11 Version 25H2 10.0.26200.0 < 10.0.26200.7623

Windows Server 2025 (Server Core installation) x64-based Systems 10.0.26100.0 < 10.0.26100.32230

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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