{"id":"CVE-2021-28481","aliases":["EUVD-2021-15159","GHSA-hj49-fxwm-2v87"],"status":"published","title":"Microsoft Exchange Server Remote Code Execution Vulnerability","description":"Microsoft Exchange Server Remote Code Execution Vulnerability","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.36237,"percentile":0.98491,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2021-04-13T19:33:47Z","modified":"2026-06-17T03:46:26Z","exploits":[{"source":"nuclei","id":"CVE-2021-28481","title":"Microsoft Exchange - Pre-Auth SSRF / ACL Bypass (ProxyNotFound)","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-28481.yaml"}],"products":[{"vendor":"microsoft","product":"exchange_server"},{"vendor":"microsoft","product":"microsoft exchange server 2013 cumulative update 23"},{"vendor":"microsoft","product":"microsoft exchange server 2016 cumulative update 19"},{"vendor":"microsoft","product":"microsoft exchange server 2016 cumulative update 20"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 8"},{"vendor":"microsoft","product":"microsoft exchange server 2019 cumulative update 9"}],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28481","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28481"},{"url":"https://github.com/advisories/GHSA-hj49-fxwm-2v87"}],"sources":{"cve":[{"id":"CVE-2021-28481","title":"Microsoft Exchange Server Remote Code Execution Vulnerability","description":"Microsoft Exchange Server Remote Code Execution Vulnerability","status":"published","published":"2021-04-13T19:33:47Z","modified":"2024-08-03T21:47:31.811Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical","assessor":"cna"}],"updated_at":"2026-11-02T14:33:08.811269Z"}],"euvd":[{"id":"EUVD-2021-15159","description":"Microsoft Exchange Server Remote Code Execution Vulnerability","status":"published","published":"2021-04-13T19:33:47Z","modified":"2024-08-03T21:47:31Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"critical"}],"updated_at":"2026-11-03T03:24:46.751124Z"}],"ghsa":[{"id":"GHSA-hj49-fxwm-2v87","title":"Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021...","description":"Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-28480, CVE-2021-28482, CVE-2021-28483.","status":"published","published":"2022-05-24T17:47:28Z","modified":"2023-12-29T03:30:28Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T14:55:17.557989Z"}],"nvd":[{"id":"CVE-2021-28481","description":"Microsoft Exchange Server Remote Code Execution Vulnerability","status":"published","published":"2021-04-13T20:15:21.53Z","modified":"2026-06-17T03:46:26.577Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"},{"version":"2.0","score":10,"vector":"AV:N/AC:L/Au:N/C:C/I:C/A:C","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:06:51.610648Z"}]}}