{"id":"CVE-2026-56020","aliases":["EUVD-2026-37909","GHSA-23xj-gfh3-wf2h"],"status":"published","title":"Webmin HTTP header authentication bypass","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.","severity":{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00495,"percentile":0.42799,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-290"],"published":"2026-06-18T16:12:05Z","modified":"2026-10-28T02:30:26Z","products":[{"vendor":"webmin","product":"webmin"}],"references":[{"url":"https://github.com/webmin/webmin/releases/tag/2.202","tags":["release-notes","advisory"]},{"url":"https://webmin.com/security/#webmin-prior-to-2202","tags":["release-notes","advisory"]},{"url":"https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-169-02.json","tags":["web"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-56020","tags":["vdb-entry","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56020","tags":["advisory"]},{"url":"https://github.com/webmin/webmin/releases/tag/2.641"},{"url":"https://webmin.com/security/#webmin-prior-to-2641"},{"url":"https://github.com/advisories/GHSA-23xj-gfh3-wf2h"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56020.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-56020","title":"Webmin HTTP header authentication bypass","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.","status":"published","published":"2026-06-18T16:12:05.368Z","modified":"2026-08-11T15:33:27.67Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T13:37:02.780526Z"}],"euvd":[{"id":"EUVD-2026-37909","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.","status":"published","published":"2026-06-18T16:12:05Z","modified":"2026-08-11T15:33:27Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical"}],"updated_at":"2026-11-02T18:01:59.926728Z"}],"ghsa":[{"id":"GHSA-23xj-gfh3-wf2h","title":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user...","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.641.","status":"published","published":"2026-06-18T18:35:24Z","modified":"2026-08-11T18:31:39Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"},{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T15:10:19.387522Z"}],"nvd":[{"id":"CVE-2026-56020","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.","status":"published","published":"2026-06-18T17:16:35.247Z","modified":"2026-08-11T16:17:33.077Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T14:12:24.912854Z"}],"osv":[{"id":"CVE-2026-56020","title":"Webmin HTTP header authentication bypass","description":"The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.202.","status":"published","published":"2026-06-18T16:12:05.368Z","modified":"2026-10-28T02:30:26.877528431Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical"}],"cwes":["CWE-290"],"updated_at":"2026-11-02T15:45:11.609219Z"}]}}