CVE-2026-21251

high Microsoft
CVSS v3 Base Score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
EPSS Score
0.0%
Exploitation probability in 30 days
Top 93% most likely to be exploited
Attack Characteristics
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: February 10, 2026 (93 days ago)
Last Modified: March 13, 2026
Vendor: Microsoft
Source: MITRE

Description

Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.

CWE

CWE-416

Affected Products

Microsoft Windows Server 2016Microsoft Windows Server 2016 (Server Core installation)Microsoft Windows Server 2019Microsoft Windows Server 2019 (Server Core installation)Microsoft Windows Server 2022Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)Microsoft Windows Server 2025Microsoft Windows Server 2025 (Server Core installation)

References

🔗 msrc.microsoft.com