CVE-2026-88099

Windows Failover Cluster Denial of Service Vulnerability

State: Published
Severity: 5.9 Medium
Published: Oct 13, 2026
Updated: Oct 31, 2026
Reserved: Sep 9, 2026

Description

Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.

Scores

CVSS	Score	Vector	Source
3.1	5.9 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-248 Uncaught Exception

Affected Products

Product	Versions
Windows Server 2019Microsoft	10.0.17763.0 to before 10.0.17763.9376Affected
Windows Server 2019 (Server Core installation)Microsoft	10.0.17763.0 to before 10.0.17763.9376Affected
Windows Server 2022Microsoft	10.0.20348.0 to before 10.0.20348.5761Affected
Windows Server 2025Microsoft	10.0.26100.0 to before 10.0.26100.33650Affected
Windows Server 2025 (Server Core installation)Microsoft	10.0.26100.0 to before 10.0.26100.33650Affected

References

Windows Failover Cluster Denial of Service Vulnerabilityvendor-advisorypatch

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