Cluster Client Failover (CCF) Elevation of Privilege Vulnerability
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describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-21251US | — | — | ||
Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally. | ||||
references
External citations — patches, advisories, analysis.
- CVE-2026-21251 Cluster Client Failover (CCF) Elevation of Privilege Vulnerability - CSAFself
- CVE-2026-21251 Cluster Client Failover (CCF) Elevation of Privilege Vulnerability - HTMLself
- Microsoft Support Lifecycleexternal
- Common Vulnerability Scoring Systemexternal
- Microsoft Exploitability Indexexternal
remediations (9)
- FixedWindows Server 2016
10.0.14393.8868:Security Update:https://support.microsoft.com/help/5075999
https://support.microsoft.com/help/5075999 - FixedWindows Server 2016 (Server Core installation)
10.0.14393.8868:Security Update:https://support.microsoft.com/help/5075999
https://support.microsoft.com/help/5075999 - FixedWindows Server 2019
10.0.17763.8389:Security Update:https://support.microsoft.com/help/5075904
https://support.microsoft.com/help/5075904 - FixedWindows Server 2019 (Server Core installation)
10.0.17763.8389:Security Update:https://support.microsoft.com/help/5075904
https://support.microsoft.com/help/5075904 - FixedWindows Server 2022
10.0.20348.4773:Security Update:https://support.microsoft.com/help/5075906
https://support.microsoft.com/help/5075906 - FixedWindows Server 2022 (Server Core installation)
10.0.20348.4773:Security Update:https://support.microsoft.com/help/5075906
https://support.microsoft.com/help/5075906 - FixedWindows Server 2022, 23H2 Edition (Server Core installation)
10.0.25398.2149:Security Update:https://support.microsoft.com/help/5075897
https://support.microsoft.com/help/5075897 - FixedWindows Server 2025
10.0.26100.32370:Security Update:https://support.microsoft.com/help/5075899
https://support.microsoft.com/help/5075899 - FixedWindows Server 2025 (Server Core installation)
10.0.26100.32370:Security Update:https://support.microsoft.com/help/5075899
https://support.microsoft.com/help/5075899
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