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Windows Failover Cluster

CVE-2026-88102 — Microsoft Failover Cluster Remote Code Execution Vulnerability

Important CVSS 9.8 2026-10 archive

Executive Summary

Use after free in Windows Failover Cluster allows an unauthorized attacker to execute code over a network.

Overview

9.8
CVSS CRITICAL
Important
MS Severity
Not Exploited
MS Exploit Status
Exploitation Unlikely
MS Exploit Likelihood
Category Remote Code Execution
Weakness CWE-416: Use After Free
Released Oct 13 2026
Last Updated Oct 13 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known

CVSS Vector

ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 8.5

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

6 affected products
Product KB Article Severity Impact Restart Required
Windows Server 2019 5126651 (Security Update) Important Remote Code Execution Yes
Windows Server 2019 (Server Core installation) 5126651 (Security Update) Important Remote Code Execution Yes
Windows Server 2022 5126655 (Security Update) Important Remote Code Execution Yes
Windows Server 2022 (Server Core installation) 5126655 (Security Update) Important Remote Code Execution Yes
Windows Server 2025 5126646 (Security Update) Important Remote Code Execution Yes
Windows Server 2025 (Server Core installation) 5126646 (Security Update) Important Remote Code Execution Yes

Patches

3 patches
Article Type Restart
5126651 Security Update Yes
5126655 Security Update Yes
5126646 Security Update Yes

Exploits & PoC

Detection Rules

Acknowledgments

41ae55e9310ff27fa6f26af4727e5590

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