CVE-2026-72989Network attack vector

Unauthenticated network information disclosure

Published Sep 8, 2026 · Updated Sep 9, 2026

Use of an uninitialized resource in Microsoft Windows Failover Cluster allows remote attackers to disclose information over a network. Microsoft does not identify the resource, code locus, triggering request, or data returned by the affected component. Exploitation requires network reachability but no authentication or user interaction, and the published impact is limited to reading information.

CVSS severityUnavailable
Unscored
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of an uninitialized resource in Microsoft Windows Failover Cluster allows remote attackers to disclose information over a network. Microsoft does not identify the resource, code locus, triggering request, or data returned by the affected component. Exploitation requires network reachability but no authentication or user interaction, and the published impact is limited to reading information.

The record

CVE
CVE-2026-72989
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-908
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.17763.0 <10.0.17763.9245

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.9245
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.33438
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.9245
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.5622
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.33438
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.9245

Published CVSS scores

7.5MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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