{"id":"CVE-2026-56181","aliases":["EUVD-2026-44316","GHSA-q8r6-qhxq-g78g"],"status":"published","title":"Windows Network Address Translation (NAT) Spoofing Vulnerability","description":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","severity":{"version":"3.1","score":8.3,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00276,"percentile":0.20185,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-346"],"published":"2026-07-14T17:10:17Z","modified":"2026-11-01T17:37:44Z","products":[{"vendor":"microsoft","product":"windows 11 version 24h2"},{"vendor":"microsoft","product":"windows 11 version 25h2"},{"vendor":"microsoft","product":"windows 11 version 26h1"},{"vendor":"microsoft","product":"windows server 2025"},{"vendor":"microsoft","product":"windows server 2025 (server core installation)"},{"vendor":"microsoft","product":"windows_11_24h2"},{"vendor":"microsoft","product":"windows_11_25h2"},{"vendor":"microsoft","product":"windows_11_26h1"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56181","tags":["vendor-advisory","patch","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56181"},{"url":"https://github.com/advisories/GHSA-q8r6-qhxq-g78g"}],"sources":{"cve":[{"id":"CVE-2026-56181","title":"Windows Network Address Translation (NAT) Spoofing Vulnerability","description":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","status":"published","published":"2026-07-14T17:10:17.039Z","modified":"2026-11-01T17:37:44.731Z","cvss":[{"version":"3.1","score":8.3,"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","level":"high","assessor":"cna"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T13:36:51.6229Z"}],"euvd":[{"id":"EUVD-2026-44316","description":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","status":"published","published":"2026-07-14T17:10:17Z","modified":"2026-11-01T17:37:44Z","cvss":[{"version":"3.1","score":8.3,"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","level":"high"}],"updated_at":"2026-11-02T16:58:46.574424Z"}],"ghsa":[{"id":"GHSA-q8r6-qhxq-g78g","title":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized...","description":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","status":"published","published":"2026-07-14T18:32:37Z","modified":"2026-07-14T18:32:43Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T15:09:30.715875Z"}],"nvd":[{"id":"CVE-2026-56181","description":"Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.","status":"published","published":"2026-07-14T18:18:24.793Z","modified":"2026-07-22T16:18:26.147Z","cvss":[{"version":"3.1","score":8.3,"vector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:12:29.489525Z"}]}}