Unrated severityNVD Advisory· Published Feb 10, 2026· Updated Apr 10, 2026
Cluster Client Failover (CCF) Elevation of Privilege Vulnerability
CVE-2026-21251
Description
Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.
Affected products
8- Microsoft/Windows Server 2016v5Range: 10.0.14393.0
- Microsoft/Windows Server 2016 (Server Core installation)v5Range: 10.0.14393.0
- Microsoft/Windows Server 2019v5Range: 10.0.17763.0
- Microsoft/Windows Server 2019 (Server Core installation)v5Range: 10.0.17763.0
- Microsoft/Windows Server 2022v5Range: 10.0.20348.0
- Microsoft/Windows Server 2022, 23H2 Edition (Server Core installation)v5Range: 10.0.25398.0
- Microsoft/Windows Server 2025v5Range: 10.0.26100.0
- Microsoft/Windows Server 2025 (Server Core installation)v5Range: 10.0.26100.0
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
1- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21251mitrevendor-advisorypatch
News mentions
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