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

CVE-2026-21251

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

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

HIGH · CVSS 7.8 EPSS 0.00039
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-416Use After Free
▤

Affected Products & Versions

5
microsoft windows server 2016< 10.0.14393.8868
microsoft windows server 2019< 10.0.17763.8389
microsoft windows server 2022< 10.0.20348.4711
microsoft windows server 2022 23h2< 10.0.25398.2149
microsoft windows server 2025< 10.0.26100.32313
▣

Scoring & Timeline

7.8
HIGH · CVSS v3.1 · secure@microsoft.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD10 Feb 2026 · 06:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

1
msrcCVE-2026-21251Elevation of Privilege
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin