CVE-2026-40405 - Vulnerability Details - OpenCVE

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

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Vendors	Products
Microsoft	Windows 11 24h2 Windows 11 25h2 Windows 11 26h1 Windows Server 2025

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors	Products

References

Link	Providers
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405

History

Tue, 12 May 2026 20:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Tue, 12 May 2026 17:30:00 +0000

Type	Values Removed	Values Added
Description		Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.
Title		Windows TCP/IP Denial of Service Vulnerability
First Time appeared		Microsoft Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025
Weaknesses		CWE-476
CPEs		cpe:2.3:o:microsoft:windows_11_24H2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_25H2:::::::arm64:* cpe:2.3:o:microsoft:windows_11_26H1:::::::x64:* cpe:2.3:o:microsoft:windows_server_2025::::::::
Vendors & Products		Microsoft Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025
References		https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40405
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C'}`

MITRE

Status: PUBLISHED

Assigner: microsoft

Published: 2026-05-12T16:58:42.545Z

Updated: 2026-05-12T19:32:22.466Z

Reserved: 2026-04-13T00:27:50.798Z

Link: CVE-2026-40405

Vulnrichment

Updated: 2026-05-12T19:32:13.688Z

NVD

Status : Received

Published: 2026-05-12T18:17:18.310

Modified: 2026-05-12T18:17:18.310

Link: CVE-2026-40405

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-05-12T19:30:23Z

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