{"id":"CVE-2026-85818","aliases":["EUVD-2026-99528","GHSA-7j3q-9qpw-gwc7"],"status":"published","title":"Windows Schannel Spoofing Vulnerability","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","severity":{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00414,"percentile":0.36197,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-347"],"published":"2026-10-13T19:00:06Z","modified":"2026-11-10T20:38:04Z","products":[{"vendor":"microsoft","product":"windows 11 version 23h2"},{"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 11 version 26h2"},{"vendor":"microsoft","product":"windows server 2022"},{"vendor":"microsoft","product":"windows server 2025"},{"vendor":"microsoft","product":"windows server 2025 (server core installation)"},{"vendor":"microsoft","product":"windows_11_23h2"},{"vendor":"microsoft","product":"windows_11_24h2"},{"vendor":"microsoft","product":"windows_11_25h2"},{"vendor":"microsoft","product":"windows_11_26h1"},{"vendor":"microsoft","product":"windows_11_26h2"},{"vendor":"microsoft","product":"windows_server_2022"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85818","tags":["vendor-advisory","patch","Vendor Advisory","Patch"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85818"},{"url":"https://github.com/advisories/GHSA-7j3q-9qpw-gwc7"}],"sources":{"cve":[{"id":"CVE-2026-85818","title":"Windows Schannel Spoofing Vulnerability","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:00:06.943Z","modified":"2026-11-10T20:38:04.44Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna"}],"cwes":["CWE-347"],"updated_at":"2026-11-10T22:18:29.471829Z"}],"euvd":[{"id":"EUVD-2026-99528","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:00:06Z","modified":"2026-11-10T20:38:04Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical"}],"updated_at":"2026-11-10T22:23:59.977047Z"}],"ghsa":[{"id":"GHSA-7j3q-9qpw-gwc7","title":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized...","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T21:35:51Z","modified":"2026-10-13T21:35:51Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:13:17.952607Z"}],"nvd":[{"id":"CVE-2026-85818","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:21:06.667Z","modified":"2026-10-16T19:58:02.273Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:12:58.13117Z"}]}}