Windows SMB Elevation of Privilege Vulnerability

Summary

SMB Server might be susceptible to relay attacks depending on the configuration. An attacker who successfully exploited these vulnerabilities could perform relay attacks and make the users subject to elevation of privilege attacks. The SMB Server already supports mechanisms for hardening against relay attacks: SMB Server signing SMB Server Extended Protection for Authentication (EPA) Microsoft is releasing this CVE to provide customers with audit capabilities to help them to assess their environment and to identify any potential device or software incompatibility issues before deploying SMB Server hardening measures that protect against relay attacks. If you have not already enabled SMB Server hardening measures, we advise customers to take the following actions to be protected from these relay attacks: Assess your environment by utilizing the audit capabilities that we are exposing in the September 2025 security updates. See Support for Audit Events to deploy SMB Server Hardening—SMB Server Signing & SMB Server EPA. Adopt appropriate SMB Server hardening measures.

Timeline

1. Sep 9, 2025, 5:01 PM UTCCVE published
2. Sep 10, 2025, 3:55 AM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Feb 26, 2026, 5:48 PM UTCRecord last updated
4. Oct 28, 2026EPSS reached 10%

   FIRST estimates at least a 10% chance of exploitation in the next 30 days

Affected versions

• Microsoft Windows 10 Version 1507

  From 10.0.10240.0 · fixed in 10.0.10240.21128

• Microsoft Windows 10 Version 1607

  From 10.0.14393.0 · fixed in 10.0.14393.8422

• Microsoft Windows 10 Version 1809

  From 10.0.17763.0 · fixed in 10.0.17763.7792

• Microsoft Windows 10 Version 21H2

  From 10.0.19044.0 · fixed in 10.0.19044.6332

• Microsoft Windows 10 Version 22H2

  From 10.0.19045.0 · fixed in 10.0.19045.6332

• Microsoft Windows 11 version 22H2

  From 10.0.22621.0 · fixed in 10.0.22621.5909

• Microsoft Windows 11 version 22H3

  From 10.0.22631.0 · fixed in 10.0.22631.5909

• Microsoft Windows 11 Version 23H2

  From 10.0.22631.0 · fixed in 10.0.22631.5909

• Microsoft Windows 11 Version 24H2

  From 10.0.26100.0 · fixed in 10.0.26100.6584

• Microsoft Windows Server 2008 R2 Service Pack 1

  From 6.1.7601.0 · fixed in 6.1.7601.27929

• Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)

  From 6.1.7601.0 · fixed in 6.1.7601.27929

• Microsoft Windows Server 2008 Service Pack 2

  From 6.0.6003.0 · fixed in 6.0.6003.23529

• Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)

  From 6.0.6003.0 · fixed in 6.0.6003.23529

• Microsoft Windows Server 2012

  From 6.2.9200.0 · fixed in 6.2.9200.25675

• Microsoft Windows Server 2012 (Server Core installation)

  From 6.2.9200.0 · fixed in 6.2.9200.25675

• Microsoft Windows Server 2012 R2

  From 6.3.9600.0 · fixed in 6.3.9600.22774

• Microsoft Windows Server 2012 R2 (Server Core installation)

  From 6.3.9600.0 · fixed in 6.3.9600.22774

• Microsoft Windows Server 2016

  From 10.0.14393.0 · fixed in 10.0.14393.8422

• Microsoft Windows Server 2016 (Server Core installation)

  From 10.0.14393.0 · fixed in 10.0.14393.8422

• Microsoft Windows Server 2019

  From 10.0.17763.0 · fixed in 10.0.17763.7792

• Microsoft Windows Server 2019 (Server Core installation)

  From 10.0.17763.0 · fixed in 10.0.17763.7792

• Microsoft Windows Server 2022

  From 10.0.20348.0 · fixed in 10.0.20348.4171

• Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)

  From 10.0.25398.0 · fixed in 10.0.25398.1849

• Microsoft Windows Server 2025

  From 10.0.26100.0 · fixed in 10.0.26100.6584

• Microsoft Windows Server 2025 (Server Core installation)

  From 10.0.26100.0 · fixed in 10.0.26100.6584

References 3