{"id":"CVE-2026-83778","aliases":["EUVD-2026-99993","GHSA-pfq4-7qpf-f79m"],"status":"published","title":"Microsoft Internet Messaging API Remote Code Execution Vulnerability","description":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to execute code over a network.","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00912,"percentile":0.60457,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-122"],"published":"2026-10-13T19:00:54Z","modified":"2026-11-10T20:42:33Z","products":[{"vendor":"microsoft","product":"windows 10 version 1607"},{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 21h2"},{"vendor":"microsoft","product":"windows 10 version 22h2"},{"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 2012"},{"vendor":"microsoft","product":"windows server 2012 (server core installation)"},{"vendor":"microsoft","product":"windows server 2012 r2"},{"vendor":"microsoft","product":"windows server 2012 r2 (server core installation)"},{"vendor":"microsoft","product":"windows server 2016"},{"vendor":"microsoft","product":"windows server 2016 (server core installation)"},{"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)"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83778","tags":["vendor-advisory","patch"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83778"},{"url":"https://github.com/advisories/GHSA-pfq4-7qpf-f79m"}],"sources":{"cve":[{"id":"CVE-2026-83778","title":"Microsoft Internet Messaging API Remote Code Execution Vulnerability","description":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to execute code over a network.","status":"published","published":"2026-10-13T19:00:54.939Z","modified":"2026-11-10T20:42:33.969Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-122"],"updated_at":"2026-11-10T22:18:28.707469Z"}],"euvd":[{"id":"EUVD-2026-99993","description":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to execute code over a network.","status":"published","published":"2026-10-13T19:00:54Z","modified":"2026-11-10T20:42:33Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-10T22:23:57.623557Z"}],"ghsa":[{"id":"GHSA-pfq4-7qpf-f79m","title":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to...","description":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to execute code over a network.","status":"published","published":"2026-10-13T21:34:52Z","modified":"2026-10-13T21:34:52Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-122"],"updated_at":"2026-11-02T15:13:16.842321Z"}],"nvd":[{"id":"CVE-2026-83778","description":"Heap-based buffer overflow in Microsoft Internet Messaging API allows an unauthorized attacker to execute code over a network.","status":"published","published":"2026-10-13T19:20:26.563Z","modified":"2026-10-16T16:21:30.897Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-122"],"updated_at":"2026-11-02T14:12:57.603498Z"}]}}