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TI-2026-72889 Aliases CVE-2026-88099GHSA-hh53-6rv7-rjrv

Windows Failover Cluster uncaught exception allows denial of service

Priority LOW 28CWE-248Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-248.

Summary

Windows Failover Cluster in Microsoft Windows Server 2019, 2022 and 2025, including Server Core installations, contains an uncaught exception (CWE-248). An unauthorized attacker can deny service over the network. Affected builds are 10.0.17763.0 before 10.0.17763.9376 for Server 2019, 10.0.20348.0 before 10.0.20348.5761 for Server 2022, and 10.0.26100.0 before 10.0.26100.33650 for Server 2025.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00818 57th percentileScored 2026-11-07
Fix Fixed Windows Server 2019 (Microsoft): 10.0.17763.9376Windows Server 2019 (Server Core installation) (Microsoft): 10.0.17763.9376+3 more products

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftWindows Server 201910.0.17763.0 to before 10.0.17763.937610.0.17763.9376Patch availableCNA
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 to before 10.0.17763.937610.0.17763.9376Patch availableCNA
MicrosoftWindows Server 202210.0.20348.0 to before 10.0.20348.576110.0.20348.5761Patch availableCNA
MicrosoftWindows Server 202510.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
  • Windows Server 2019 VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
  • Windows Server 2019 (Server Core installation) VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
  • Windows Server 2022 VendorMicrosoft Affected 10.0.20348.0 to before 10.0.20348.5761 Fixed in 10.0.20348.5761 Patch available CNA
  • Windows Server 2025 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA
  • Windows Server 2025 (Server Core installation) VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:*before 10.0.17763.9376VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*before 10.0.20348.5761VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*before 10.0.26100.33650VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:* Versions before 10.0.17763.9376 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:* Versions before 10.0.20348.5761 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:* Versions before 10.0.26100.33650 Vulnerable ·Microsoft

Remediation

Install 10.0.17763.9376 on Windows Server 2019 and its Server Core installation, 10.0.20348.5761 on Windows Server 2022, and 10.0.26100.33650 on Windows Server 2025 and its Server Core installation.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA Windows Server 2019 (Microsoft) Fixed in 10.0.17763.9376
  • Fix · CNA Windows Server 2019 (Server Core installation) (Microsoft) Fixed in 10.0.17763.9376
  • Fix · CNA Windows Server 2022 (Microsoft) Fixed in 10.0.20348.5761
  • Fix · CNA Windows Server 2025 (Microsoft) Fixed in 10.0.26100.33650
  • Fix · CNA Windows Server 2025 (Server Core installation) (Microsoft) Fixed in 10.0.26100.33650

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-88099
  2. 2026-10-13 Alias added: GHSA-hh53-6rv7-rjrv

References

Patch 1

  • TI-2026-26194 Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-36863 Windows Server Update Service (WSUS) Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-01431 Netlogon Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 10.0
  • TI-2020-01310 Improper input validation in Microsoft Windows Server KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-73128 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17367 MSHTML Framework Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
See all 6455 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences