{"id":"CVE-2026-34959","summary":"Adminer before 5.5.0 Open Redirect via X-Forwarded-Prefix","details":"Adminer 4.6.0 before 5.5.0 prepends the client-supplied X-Forwarded-Prefix header to $_SERVER[\"REQUEST_URI\"] with no trusted-proxy check and no validation of the prefix value. An attacker can supply an absolute URL (e.g. X-Forwarded-Prefix: https://evil.example) that flows into Location redirect headers, the Set-Cookie path attribute, and self-referential links. This enables an authenticated open redirect after state-changing POSTs, unauthenticated control of the session cookie path attribute, and poisoning of self-referential links; CR/LF cannot be injected, so header splitting/XSS is not possible.","aliases":["GHSA-8478-xrj3-h9c2"],"modified":"2026-08-28T11:30:52.622386292Z","published":"2026-08-25T01:29:57.683Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34959.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34959.json"},{"type":"ADVISORY","url":"https://github.com/vrana/adminer/security/advisories/GHSA-8478-xrj3-h9c2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34959"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/adminer-before-open-redirect-via-x-forwarded-prefix"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/vrana/adminer","events":[{"introduced":"d2ed0f7810e4f05a2fc6348286b622abf6464751"},{"fixed":"94dc72bba68fdb6e981abca35bafd315a7e776eb"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"5.5.0"},{"introduced":"4.6.0"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["v5.4.4","v5.4.3","v5.4.2","v5.4.1","v5.4.0","v5.3.0","v5.2.1","v5.2.0","v5.1.1","v5.1.0","v5.0.6","v5.0.5","v5.0.4","v5.0.3","v5.0.2","v5.0.1","v5.0.0","v4.17.1","v4.17.0","v4.16.0","v4.8.1","v4.8.0","v4.7.9","v4.7.8","v4.7.7","v4.7.5","v4.7.4","v4.7.3","v4.7.2","v4.7.1","v4.7.0","v4.6.3","v4.6.2","v4.6.1","v4.6.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34959.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"}]}