CVE-2026-40405

Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:microsoft:windows_11_24h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_24h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_25h2:::::::x64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::arm64:*
	cpe:2.3:o:microsoft:windows_11_26h1:::::::x64:*
	cpe:2.3:o:microsoft:windows_server_2025::::::::

History

15 May 2026, 15:20

Type	Values Removed	Values Added
References	~~() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405 -~~	() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405 - Vendor Advisory
First Time		Microsoft Microsoft windows Server 2025 Microsoft windows 11 26h1 Microsoft windows 11 25h2 Microsoft windows 11 24h2
CPE		cpe:2.3:o:microsoft:windows_11_25h2:::::::x64:* cpe:2.3:o:microsoft:windows_11_24h2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_25h2:::::::arm64:* cpe:2.3:o:microsoft:windows_server_2025:::::::: cpe:2.3:o:microsoft:windows_11_24h2:::::::x64:* cpe:2.3:o:microsoft:windows_11_26h1:::::::x64:* cpe:2.3:o:microsoft:windows_11_26h1:::::::arm64:*

12 May 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-12 18:17

Updated : 2026-05-15 15:20

NVD link : CVE-2026-40405

Mitre link : CVE-2026-40405

CVE.ORG link : CVE-2026-40405

JSON object : View

Products Affected

microsoft

windows_11_25h2
windows_11_24h2
windows_11_26h1
windows_server_2025

CWE

CWE-476

NULL Pointer Dereference

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