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Fencer Intel
high 8.3

CVE-2026-56179 json

Windows Network Address Translation (NAT) Spoofing Vulnerability

published 3mo ago modified yesterday also EUVD-2026-56763

cvss
8.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

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

Patch / fix

  • Microsoft Windows 11 Version 24H2 10.0.26100.9168
  • Microsoft Windows 11 Version 25H2 10.0.26200.9168
  • Microsoft Windows 11 version 26H1 10.0.28000.2704
  • Microsoft Windows Server 2025 10.0.26100.33296
  • Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.33296

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 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
CNA 3.1 8.3 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Microsoft Windows 11 Version 24H2
  • Microsoft Windows 11 Version 25H2
  • Microsoft Windows 11 version 26H1
  • Microsoft Windows Server 2025
  • Microsoft Windows Server 2025 (Server Core installation)

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.