# CVE-2026-56179

## Summary

- **CVE ID:** CVE-2026-56179
- **Severity:** HIGH
- **CVSS Score:** 8.3 (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)
- **CWE:** CWE-346
- **Published:** Aug 11, 2026
- **Last Modified:** Sep 16, 2026

## 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 Version 24H2 (10.0.26100.0)
- Microsoft — Windows 11 Version 25H2 (10.0.26200.0)
- Microsoft — Windows 11 version 26H1 (10.0.28000.0)
- Microsoft — Windows Server 2025 (10.0.26100.0)
- Microsoft — Windows Server 2025 (Server Core installation) (10.0.26100.0)

## References

- [CNA](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56179)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.23%
- **EPSS Percentile:** 14.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._