CVE-2026-56181

Status: AnalyzedHigh (8.3)—

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

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Base score: 8.3

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.28%
Percentile among all scored CVEs: 18
Score date: 10/4/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1210 Exploitation of Remote Serviceslateral movement60 %

Inferred by deterministic rules from the CVSS vector and CWE. Indicative only.

🛡️ ATT&CK mitigations that cover these techniques

Vulnerability Scanning Threat Intelligence Program Privileged Account Management Network Segmentation Disable or Remove Feature or Program Application Isolation and Sandboxing

Affected technologies (4)

Microsoft — Windows 11 24h2 Microsoft — Windows 11 25h2 Microsoft — Windows 11 26h1 Microsoft — Windows Server 2025

CWEs

CWE-346

References

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

Raw JSON (NVD)

Show

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  "lastModified": "2026-07-22T16:18:26.147",
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