NULL pointer dereference in Microsoft Windows and Windows Server - CVE-2026-56168
Published: July 17, 2026
Vulnerability identifier: #VU138115
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-56168
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a null pointer dereference in Windows SMB Server when handling network requests. A remote user can send a specially crafted request to cause a denial of service.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-56168
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7548, 10 22H2 10.0.19045.7548, 11 24H2 10.0.26100.8875, 11 25H2 10.0.26200.8875, 11 26H1 10.0.28000.2269, 11 26H1 10.0.28000.2525
Windows Server - addressed in versions 2012 R2 6.3.9600.23291, 2022 10.0.20348.5386, 2025 10.0.26100.33158
Windows Server - addressed in versions 2012 R2 6.3.9600.23291, 2022 10.0.20348.5386, 2025 10.0.26100.33158