{"id":"CVE-2025-53809","aliases":["EUVD-2025-27321","GHSA-45gp-pfc8-39m2"],"status":"published","title":"Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability","description":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.01573,"percentile":0.75768,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2025-09-09T17:01:16Z","modified":"2026-10-18T21:10:00Z","products":[{"vendor":"microsoft","product":"windows 11 version 24h2"},{"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_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53809","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-53809"},{"url":"https://github.com/advisories/GHSA-45gp-pfc8-39m2"}],"sources":{"cve":[{"id":"CVE-2025-53809","title":"Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability","description":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.","status":"published","published":"2025-09-09T17:01:16.552Z","modified":"2026-02-20T16:00:47.255Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:32:49.180768Z"}],"euvd":[{"id":"EUVD-2025-27321","description":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.","status":"published","published":"2025-09-09T17:01:16Z","modified":"2026-02-20T16:00:47Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T19:48:36.672162Z"}],"ghsa":[{"id":"GHSA-45gp-pfc8-39m2","title":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an...","description":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.","status":"published","published":"2025-09-09T18:31:20Z","modified":"2025-09-09T18:31:26Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:03:32.650929Z"}],"nvd":[{"id":"CVE-2025-53809","description":"Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.","status":"published","published":"2025-09-09T17:15:52.163Z","modified":"2026-10-18T21:10:00.12Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:11:27.73916Z"}]}}