CVE-2026-56181 - Vulnerability Details - OpenCVE

Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.

No CVSS v4.0

Attack Vector Adjacent Network

Attack Complexity High

Privileges Required None

Scope Changed

Confidentiality Impact High

Integrity Impact High

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 no

Technical Impact total

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

No data.

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References

Link	Providers
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56181

History

Tue, 14 Jul 2026 20:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Tue, 14 Jul 2026 17:45:00 +0000

Type	Values Removed	Values Added
Description		Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
Title		Windows Network Address Translation (NAT) Spoofing Vulnerability
First Time appeared		Microsoft Microsoft windows 11 24h2 Microsoft windows 11 25h2 Microsoft windows 11 26h1 Microsoft windows Server 2025
Weaknesses		CWE-346
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-2026-56181
Metrics		cvssV3_1 `{'score': 8.3, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C'}`

MITRE

Status: PUBLISHED

Assigner: microsoft

Published: 2026-07-14T17:10:17.039Z

Updated: 2026-07-14T19:42:37.239Z

Reserved: 2026-06-19T13:54:04.005Z

Link: CVE-2026-56181

Vulnrichment

Updated: 2026-07-14T17:47:17.599Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

No data.

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