{"id":"CVE-2026-121491","aliases":["EUVD-2026-118943","GHSA-qr57-vj96-mp6j"],"status":"published","title":"Fiber Admin 3.1.0 - 4.0.0 - Unauthenticated RCE via Host Header","description":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","severity":{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-12","score":0.00395,"percentile":0.34206,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-94"],"published":"2026-11-07T06:00:26Z","modified":"2026-11-07T18:16:15Z","products":[{"vendor":"unknown","product":"fiber admin"}],"references":[{"url":"https://wpscan.com/vulnerability/42b9773d-9c69-4435-be20-ae86f52b4608/","tags":["exploit","vdb-entry","technical-description"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121491"},{"url":"https://wpscan.com/vulnerability/42b9773d-9c69-4435-be20-ae86f52b4608"},{"url":"https://github.com/advisories/GHSA-qr57-vj96-mp6j"}],"sources":{"cve":[{"id":"CVE-2026-121491","title":"Fiber Admin 3.1.0 - 4.0.0 - Unauthenticated RCE via Host Header","description":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","status":"published","published":"2026-11-07T06:00:26.885Z","modified":"2026-11-07T18:16:15.338Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"adp"}],"cwes":["CWE-94"],"updated_at":"2026-11-07T19:35:26.456285Z"}],"euvd":[{"id":"EUVD-2026-118943","description":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","status":"published","published":"2026-11-07T06:00:26Z","modified":"2026-11-07T18:16:15Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-07T19:10:17.704886Z"}],"ghsa":[{"id":"GHSA-qr57-vj96-mp6j","title":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before...","description":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","status":"published","published":"2026-11-07T06:31:24Z","modified":"2026-11-07T21:32:14Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-94"],"updated_at":"2026-11-07T21:39:59.065692Z"}],"nvd":[{"id":"CVE-2026-121491","description":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","status":"published","published":"2026-11-07T06:16:58.28Z","modified":"2026-11-10T16:28:46.51Z","cvss":[{"version":"3.1","score":9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-94"],"updated_at":"2026-11-07T22:06:52.100138Z"}]}}