{"id":"CVE-2026-40405","aliases":["EUVD-2026-29665","GHSA-mj3g-9j9x-c556"],"status":"published","title":"Windows TCP/IP Denial of Service Vulnerability","description":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01078,"percentile":0.65461,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-476"],"published":"2026-05-12T16:58:42Z","modified":"2026-08-10T15:12:54Z","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-2026-40405","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40405"},{"url":"https://github.com/advisories/GHSA-mj3g-9j9x-c556"}],"sources":{"cve":[{"id":"CVE-2026-40405","title":"Windows TCP/IP Denial of Service Vulnerability","description":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-05-12T16:58:42.545Z","modified":"2026-08-10T15:12:54.079Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T13:43:11.445168Z"}],"euvd":[{"id":"EUVD-2026-29665","description":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-05-12T16:58:42Z","modified":"2026-08-10T15:12:54Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T18:02:02.865075Z"}],"ghsa":[{"id":"GHSA-mj3g-9j9x-c556","title":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a...","description":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-05-12T18:30:45Z","modified":"2026-05-12T18:30:50Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T15:08:05.647564Z"}],"nvd":[{"id":"CVE-2026-40405","description":"Null pointer dereference in Windows TCP/IP allows an unauthorized attacker to deny service over a network.","status":"published","published":"2026-05-12T18:17:18.31Z","modified":"2026-06-17T10:45:15.66Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:12:18.613259Z"}]}}