CVE-2026-25177: Active Directory Domain Services Elevation of Privilege Vulnerability

Overview

Severity
High (CVSS 8.8)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Elevation of Privilege
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Mar
Released
2026-03-10
EPSS Score
0.07% (percentile: 21.8%)

Description

Improper restriction of names for files and other resources in Active Directory Domain Services allows an authorized attacker to elevate privileges over a network.

FAQ

What privileges could be gained by an attacker who successfully exploited this vulnerability? An attacker who successfully exploited this vulnerability could gain SYSTEM privileges. How could an attacker exploit this vulnerability? An attacker could exploit this issue by adding specially crafted Unicode characters to duplicate Service Principal Names (SPNs) or User Principal Names (UPNs). These characters bypass normal Active Directory checks designed to prevent duplicates. If the attacker has permission to modify SPNs on any account, they can create a duplicate SPN for a targeted service. When clients request Kerberos authentication for that service, the domain controller may issue a ticket encrypted with the wrong key, causing the service to reject the ticket. This can lead to a denial of service or force the service to fall back to NTLM authentication if it is enabled. No access to the targeted server is required beyond the initial SPN‑write permission.

Affected Products (31)

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 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for x64-based Systems
  • 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 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)
  • Windows 11 Version 26H1 for ARM64-based Systems
  • Windows 11 version 26H1 for x64-based Systems

ESU

  • 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 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)

Security Updates (12)

Acknowledgments

<a href="https://www.linkedin.com/in/shailaron">Shai Laron</a> with Semperis

Revision History

  • 2026-03-10: Information published.