{"id":"CVE-2026-83906","aliases":["EUVD-2026-99431","GHSA-3h8c-pxq9-g5j2"],"status":"published","title":"Windows Shell Spoofing Vulnerability","description":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized attacker to perform spoofing over a network.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0099,"percentile":0.6294,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-303"],"published":"2026-10-13T18:59:57Z","modified":"2026-11-10T20:37:07Z","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 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_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83906","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83906"},{"url":"https://github.com/advisories/GHSA-3h8c-pxq9-g5j2"}],"sources":{"cve":[{"id":"CVE-2026-83906","title":"Windows Shell Spoofing Vulnerability","description":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T18:59:57.544Z","modified":"2026-11-10T20:37:07.094Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-303"],"updated_at":"2026-11-10T22:18:28.707469Z"}],"euvd":[{"id":"EUVD-2026-99431","description":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T18:59:57Z","modified":"2026-11-10T20:37:07Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-10T21:23:21.470164Z"}],"ghsa":[{"id":"GHSA-3h8c-pxq9-g5j2","title":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized...","description":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T21:35:07Z","modified":"2026-10-13T21:35:14Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T15:13:17.40783Z"}],"nvd":[{"id":"CVE-2026-83906","description":"Incorrect implementation of authentication algorithm in Windows Shell allows an unauthorized attacker to perform spoofing over a network.","status":"published","published":"2026-10-13T19:20:45.4Z","modified":"2026-10-29T18:20:21.92Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T14:12:58.13117Z"}]}}