{"id":"CVE-2021-38751","aliases":["EUVD-2021-25188","GHSA-mg75-hvvv-r45q"],"status":"published","title":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A...","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.02468,"percentile":0.84611,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-116"],"published":"2021-08-16T13:53:19Z","modified":"2026-10-20T10:54:52Z","exploits":[{"source":"nuclei","id":"CVE-2021-38751","title":"ExponentCMS \u003c= 2.6 - Host Header Injection","type":"detection template","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-38751.yaml"}],"products":[{"vendor":"exponentcms","product":"exponentcms"}],"references":[{"url":"https://github.com/exponentcms/exponent-cms/issues/1544","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38751"},{"url":"https://github.com/advisories/GHSA-mg75-hvvv-r45q"}],"sources":{"cve":[{"id":"CVE-2021-38751","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","status":"published","published":"2021-08-16T13:53:19Z","modified":"2024-08-04T01:51:20.357Z","updated_at":"2026-11-02T14:33:07.349244Z"}],"euvd":[{"id":"EUVD-2021-25188","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","status":"published","published":"2021-08-16T13:53:19Z","modified":"2024-08-04T01:51:20Z","updated_at":"2026-11-03T03:24:24.305495Z"}],"ghsa":[{"id":"GHSA-mg75-hvvv-r45q","title":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A...","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","status":"published","published":"2022-05-24T19:11:16Z","modified":"2023-01-30T05:01:33Z","cwes":["CWE-116"],"updated_at":"2026-11-02T14:46:25.989719Z"}],"nvd":[{"id":"CVE-2021-38751","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","status":"published","published":"2021-08-16T14:15:07.1Z","modified":"2026-06-17T04:02:41.007Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-116"],"updated_at":"2026-11-02T14:06:56.943671Z"}],"osv":[{"id":"CVE-2021-38751","description":"A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.","status":"published","published":"2021-08-16T14:15:07.1Z","modified":"2026-10-20T10:54:52.1776081Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:20.843843Z"}]}}