Use of uninitialized resource in Windows and Windows Server - CVE-2026-56190
Published: July 17, 2026
Vulnerability identifier: #VU138119
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-56190
CWE-ID: CWE-908
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Windows
Windows Server
Windows
Windows Server
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use of uninitialized resource in Windows RDP when handling specially crafted Remote Desktop Protocol traffic. A remote attacker can send specially crafted RDP traffic to execute arbitrary code.
Exploitation requires that Network Level Authentication (NLA) be disabled on the target system.
How to mitigate CVE-2026-56190
Install security update from vendor's website.