Vulnerability Description
Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
CVSS Score
8.3
HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 11 24H2 | < 10.0.26100.8875 |
| Microsoft | Windows 11 25H2 | < 10.0.26200.8875 |
| Microsoft | Windows 11 26H1 | < 10.0.28000.2525 |
| Microsoft | Windows Server 2025 | < 10.0.26100.33158 |
Related Weaknesses (CWE)
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56181PatchVendor Advisory
FAQ
What is CVE-2026-56181?
CVE-2026-56181 is a vulnerability with a CVSS score of 8.3 (HIGH). Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
How severe is CVE-2026-56181?
CVE-2026-56181 has been rated HIGH with a CVSS base score of 8.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-56181?
Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 11 24H2, Microsoft Windows 11 25H2, Microsoft Windows 11 26H1, Microsoft Windows Server 2025.