MSRC-CVE-2026-72989 — Windows Failover Cluster Information Disclosure Vulnerability

Summary

Impact: Information Disclosure. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

What type of information could be disclosed by this vulnerability?
The type of information that could be disclosed if an attacker successfully exploited this vulnerability is uninitialized stack memory.

Security updates
10.0.17763.9245 — https://support.microsoft.com/help/5122876
10.0.20348.5622 — https://support.microsoft.com/help/5122882
10.0.26100.33438 — https://support.microsoft.com/help/5122871

Vulnerabilities 1

High 7.5

CVE-2026-72989

Windows Failover Cluster Information Disclosure Vulnerability

Use of uninitialized resource in Windows Failover Cluster allows an unauthorized attacker to disclose information over a network.

Microsoft Windows Server 2019 Windows Server 2019 (Server Core installation) Windows 10 Version 1809 Windows

Sep 8, 2026

Revision history

2026-09-08 #1
Information published.

References

CVE-2026-72989 Windows Failover Cluster Information Disclosure Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72989
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss