Description
Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.
Affected products
microsoft: windows 11 24h2; microsoft: windows 11 25h2; microsoft: windows 11 26h1; microsoft: windows server 2025
References1
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56179 PatchVendor Advisory
Metrics
- CVSS 3.1
-
8.3
HIGH
Score source: CNA
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 20 · as of 12 November 2026
- CWE
- CWE-346
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.