CVE-2026-56179 PUBLISHED

Windows Network Address Translation (NAT) Spoofing Vulnerability

Assigner: microsoft
Reserved: 19.06.2026 Published: 11.08.2026 Updated: 12.08.2026

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

Metrics

CVSS Vector: 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
CVSS Score: 8.3

Product Status

Vendor Microsoft
Product Windows 11 Version 24H2
Versions
  • affected from 10.0.26100.0 to 10.0.26100.9168 (excl.)
Vendor Microsoft
Product Windows 11 Version 25H2
Versions
  • affected from 10.0.26200.0 to 10.0.26200.9168 (excl.)
Vendor Microsoft
Product Windows 11 version 26H1
Versions
  • affected from 10.0.28000.0 to 10.0.28000.2704 (excl.)
Vendor Microsoft
Product Windows Server 2025
Versions
  • affected from 10.0.26100.0 to 10.0.26100.33296 (excl.)
Vendor Microsoft
Product Windows Server 2025 (Server Core installation)
Versions
  • affected from 10.0.26100.0 to 10.0.26100.33296 (excl.)

References

Problem Types