{"id":"CVE-2026-88099","aliases":["EUVD-2026-99651","GHSA-hh53-6rv7-rjrv"],"status":"published","title":"Windows Failover Cluster Denial of Service Vulnerability","description":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00818,"percentile":0.57435,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-248"],"published":"2026-10-13T19:00:20Z","modified":"2026-10-31T18:05:54Z","products":[{"vendor":"microsoft","product":"windows server 2019"},{"vendor":"microsoft","product":"windows server 2019 (server core installation)"},{"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_server_2019"},{"vendor":"microsoft","product":"windows_server_2022"},{"vendor":"microsoft","product":"windows_server_2025"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88099","tags":["vendor-advisory","patch","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88099"},{"url":"https://github.com/advisories/GHSA-hh53-6rv7-rjrv"}],"sources":{"cve":[{"id":"CVE-2026-88099","title":"Windows Failover Cluster Denial of Service Vulnerability","description":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:00:20.593Z","modified":"2026-10-31T18:05:54.016Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-248"],"updated_at":"2026-11-02T13:41:53.237769Z"}],"euvd":[{"id":"EUVD-2026-99651","description":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:00:20Z","modified":"2026-10-31T18:05:54Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T16:58:53.928041Z"}],"ghsa":[{"id":"GHSA-hh53-6rv7-rjrv","title":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service...","description":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T21:36:36Z","modified":"2026-10-13T21:36:36Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-248"],"updated_at":"2026-11-02T15:13:18.544547Z"}],"nvd":[{"id":"CVE-2026-88099","description":"Uncaught exception in Windows Failover Cluster allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-10-13T19:21:27.8Z","modified":"2026-10-16T15:43:48.16Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-248"],"updated_at":"2026-11-02T14:12:58.13117Z"}]}}