CVE-2026-102192: Windows Failover Cluster Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-31
Weakness: CWE-191

Description

Integer underflow (wrap or wraparound) in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.

Affected products

Microsoft Windows Server 2019: before 10.0.17763.9376 — fixed in 10.0.17763.9376
Microsoft Windows Server 2022: before 10.0.20348.5761 — fixed in 10.0.20348.5761
Microsoft Windows Server 2025: before 10.0.26100.33650 — fixed in 10.0.26100.33650
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.9376 — fixed in 10.0.17763.9376
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5761 — fixed in 10.0.20348.5761
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.33650 — fixed in 10.0.26100.33650

How to fix

Upgrade to a fixed version: Microsoft Windows Server 2019 10.0.17763.9376; Microsoft Windows Server 2022 10.0.20348.5761; Microsoft Windows Server 2025 10.0.26100.33650; Microsoft Windows Server 2019 10.0.17763.9376; Microsoft Windows Server 2022 10.0.20348.5761; Microsoft Windows Server 2025 10.0.26100.33650. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-102192

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