Windows Network Address Translation (NAT) Spoofing VulnerabilityVendor advisorypatch
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56179 CVE-2026-56179
HIGH
Windows Network Address Translation (NAT) Spoofing Vulnerability
Record summary
CVE-2026-56179 has a selected CVSS score of 8.3 (high).
Description
Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
Description source: GitHub Advisory
Exploitation context
CISA SSVC decision
ExploitationNone
AutomatableNo
Technical impactTotal
CISA Coordinator · SSVC 2.0.3 · Evaluated Aug 13, 2026 · Source: CVE List
Affected products and versions
5| Product | Source | Version range | Status |
|---|---|---|---|
Windows 11 Version 24H2Browse Microsoft / Windows 11 Version 24H2 | CVE List | 10.0.26100.0 to < 10.0.26100.9168 | affected |
Windows 11 Version 25H2Browse Microsoft / Windows 11 Version 25H2 | CVE List | 10.0.26200.0 to < 10.0.26200.9168 | affected |
Windows 11 version 26H1Browse Microsoft / Windows 11 version 26H1 | CVE List | 10.0.28000.0 to < 10.0.28000.2704 | affected |
Windows Server 2025Browse Microsoft / Windows Server 2025 | CVE List | 10.0.26100.0 to < 10.0.26100.33296 | affected |
Windows Server 2025 (Server Core installation)Browse Microsoft / Windows Server 2025 (Server Core installation) | CVE List | 10.0.26100.0 to < 10.0.26100.33296 | affected |
References
2nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2026-56179