CVE-2026-55001: Active Directory Domain Services Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 7.8)

CVSS Vector

CVSS:3.1/AV:L/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-Jul

Released

2026-07-14

Description

Improper certificate validation in Windows Active Directory allows an authorized attacker to elevate privileges locally.

FAQ

What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker who successfully exploited this vulnerability could gain administrator privileges.

Affected Products (11)

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 2025 (Server Core installation)
• 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)

Security Updates (4)

• 5099538
• 5099540
• 5099536
• 5099535

Acknowledgments

Anonymous

Revision History

• 2026-07-14: Information published.