{"id":"CVE-2021-26443","aliases":["EUVD-2021-13248","GHSA-v594-fc8g-fg3j"],"status":"published","title":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","description":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","severity":{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01696,"percentile":0.77459,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2021-11-10T00:46:21Z","modified":"2026-08-19T18:32:36Z","products":[{"vendor":"microsoft","product":"windows 10 version 1809"},{"vendor":"microsoft","product":"windows 10 version 1909"},{"vendor":"microsoft","product":"windows 10 version 2004"},{"vendor":"microsoft","product":"windows 10 version 21h1"},{"vendor":"microsoft","product":"windows 11 version 21h2"},{"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 version 2004"},{"vendor":"microsoft","product":"windows server version 20h2"},{"vendor":"microsoft","product":"windows_10"},{"vendor":"microsoft","product":"windows_11"},{"vendor":"microsoft","product":"windows_server_2016"},{"vendor":"microsoft","product":"windows_server_2019"},{"vendor":"microsoft","product":"windows_server_2022"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26443","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26443","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26443"},{"url":"https://github.com/advisories/GHSA-v594-fc8g-fg3j"}],"sources":{"cve":[{"id":"CVE-2021-26443","title":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","description":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","status":"published","published":"2021-11-10T00:46:21Z","modified":"2026-08-19T16:26:57.497Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna"}],"updated_at":"2026-11-02T14:32:57.368269Z"}],"euvd":[{"id":"EUVD-2021-13248","description":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","status":"published","published":"2021-11-10T00:46:21Z","modified":"2026-08-19T16:26:57Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical"}],"updated_at":"2026-11-02T18:01:43.792814Z"}],"ghsa":[{"id":"GHSA-v594-fc8g-fg3j","title":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","description":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","status":"published","published":"2022-05-24T19:20:26Z","modified":"2026-08-19T18:32:36Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:10:42.894447Z"}],"nvd":[{"id":"CVE-2021-26443","description":"Microsoft Virtual Machine Bus (VMBus) Remote Code Execution Vulnerability","status":"published","published":"2021-11-10T01:16:35.06Z","modified":"2026-08-19T17:17:37.557Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"2.0","score":7.7,"vector":"AV:A/AC:L/Au:S/C:C/I:C/A:C","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:07:00.984108Z"}]}}