CVE-2026-33826: Windows Active Directory Remote Code Execution Vulnerability

Overview

Severity
High (CVSS 8)
CVSS Vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
More Likely
Patch Tuesday
2026-Apr
Released
2026-04-14

Description

Improper input validation in Windows Active Directory allows an authorized attacker to execute code over an adjacent network.

FAQ

How could an attacker exploit this vulnerability? To exploit this vulnerability, an authenticated attacker would need to send a specially crafted RPC call to an RPC host. This could result in remote code execution on the server side with the same permissions as the RPC service. According to the CVSS metric, the attack vector is adjacent (AV:A). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires that an attacker needs to be in the same restricted Active Directory domain as the target system. The attack surface is not reachable from broader networks, which is why the attack vector is considered adjacent (AV:A).

Affected Products (11)

Windows

  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2025 (Server Core installation)
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows Server 2025
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)

ESU

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

Security Updates (6)

Acknowledgments

<a href="https://x.com/aniqfakhrul">Aniq Fakhrul</a>

Revision History

  • 2026-04-14: Information published.