Remote Code Execution Vulnerability in Windows Local Security Authority Subsystem Service
CVE-2026-20854

7.5HIGH

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-2026-20854?

A vulnerability exists in the Windows Local Security Authority Subsystem Service (LSASS) due to a use-after-free condition that can allow an authorized attacker to execute arbitrary code remotely. This flaw can be exploited over a network, enabling potential unauthorized access to system functions and sensitive data. To mitigate this risk, users are advised to apply the latest security patches provided by Microsoft.

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:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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