CVE-2026-21251

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-21251
Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.

7.8 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21251 Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
History

11 Feb 2026, 19:42

Type Values Removed Values Added
First Time Microsoft windows Server 2022
Microsoft
Microsoft windows Server 2019
Microsoft windows Server 2016
Microsoft windows Server 2022 23h2
Microsoft windows Server 2025
CPE cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
References () https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21251 - () https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21251 - Vendor Advisory

10 Feb 2026, 18:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-02-10 18:16

Updated : 2026-02-11 19:42

NVD link : CVE-2026-21251

Mitre link : CVE-2026-21251

CVE.ORG link : CVE-2026-21251

JSON object : View

Products Affected

microsoft

  • windows_server_2025
  • windows_server_2019
  • windows_server_2022
  • windows_server_2016
  • windows_server_2022_23h2
CWE
CWE-416

Use After Free