CVE-2025-26673: Windows Lightweight Directory Access Protocol (LDAP) Denial of Service Vulnerability

Overview

Severity
High (CVSS 7.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
Category
Denial of Service
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2025-Apr
Released
2025-04-08
Last Updated
2025-05-13
EPSS Score
44.12% (percentile: 97.5%)

Description

Uncontrolled resource consumption in Windows LDAP - Lightweight Directory Access Protocol allows an unauthorized attacker to deny service over a network.

FAQ

Are the updates for Windows 10 for x64-based Systems and Windows 10 for 32-bit Systems currently available? Yes. As of April 9, 2025, the security update (5055547) for Windows 10 for x64-based Systems and Windows 10 for 32-bit Systems are available. Customers running Windows 10 should ensure the update is installed to be protected from this vulnerability.

Affected Products (37)

Windows

  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025
  • Windows 10 for 32-bit Systems
  • Windows 10 for x64-based Systems
  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows Server 2008 for 32-bit Systems Service Pack 2
  • Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 for x64-based Systems Service Pack 2
  • Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (14)

Acknowledgments

<a href="https://twitter.com/4zure9">Azure Yang</a> with <a href="http://www.cyberkl.com/">Kunlun Lab</a>, <a href="https://www.linkedin.com/in/or-yair">Or Yair</a> and Shahak Morag with <a href="https://www.safebreach.com/">SafeBreach</a>

Revision History

  • 2025-04-08: Information published.
  • 2025-04-09: The security updates for Windows 10 for 32-bit Systems and Windows 10 for x64-based Systems are now available. See the Security Updates table for more information.
  • 2025-05-13: Acknowledgement added. This is an informational change only.