{"id":"CVE-2020-26030","aliases":["EUVD-2020-18660","GHSA-7wgm-v99f-436j"],"status":"published","title":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO...","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","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","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.0135,"percentile":0.71866,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287"],"published":"2020-12-28T07:57:23Z","modified":"2026-10-24T10:30:24Z","products":[{"vendor":"zammad","product":"zammad"}],"references":[{"url":"https://zammad.com/news/security-advisory-zaa-2020-18","tags":["x_refsource_MISC","x_transferred","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26030"},{"url":"https://github.com/advisories/GHSA-7wgm-v99f-436j"}],"sources":{"cve":[{"id":"CVE-2020-26030","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","status":"published","published":"2020-12-28T07:57:23Z","modified":"2024-08-04T15:49:06.687Z","updated_at":"2026-11-02T14:35:46.129376Z"}],"euvd":[{"id":"EUVD-2020-18660","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","status":"published","published":"2020-12-28T07:57:23Z","modified":"2024-08-04T15:49:06Z","updated_at":"2026-11-03T03:07:16.308974Z"}],"ghsa":[{"id":"GHSA-7wgm-v99f-436j","title":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO...","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","status":"published","published":"2022-05-24T17:37:23Z","modified":"2023-01-29T05:05:51Z","cwes":["CWE-287"],"updated_at":"2026-11-02T14:45:53.268312Z"}],"nvd":[{"id":"CVE-2020-26030","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","status":"published","published":"2020-12-28T08:15:11.257Z","modified":"2026-06-17T03:07:29.653Z","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":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:06:28.340168Z"}],"osv":[{"id":"CVE-2020-26030","description":"An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.","status":"published","published":"2020-12-28T08:15:11.257Z","modified":"2026-10-24T10:30:24.446115125Z","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":"2026-11-02T15:44:15.879068Z"}]}}