{"id":"CVE-2026-56181","title":"Windows Network Address Translation (NAT) Spoofing Vulnerability","summary":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","severity":"high","cvss":8.3,"cvssVector":"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","cvssSource":"cna","cwe":["CWE-346"],"vendor":"Microsoft","product":"Windows 11 Version 24H2","affected":["windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875","windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875","windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525","windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158","windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-07-14T17:47:13.057988Z"},"published":"2026-07-14","updated":"2026-09-17","sourceUpdated":"2026-09-17T22:34:18.541Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-56181","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56181","label":"Windows Network Address Translation (NAT) Spoofing Vulnerability"}],"tags":["cve.org"],"epss":0.00276,"epssPercentile":0.20252,"ingestedAt":"2026-09-08T17:06:31.895Z","slug":"CVE-2026-56181","body":"## Overview\n\nOrigin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.\n\n## Affected\n\n- `windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.8875`\n- `windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.8875`\n- `windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.2525`\n- `windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33158`\n- `windows_server_2025_server_core_installation >= 10.0.26100.0 < 10.0.26100.33158`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":45.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}