{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "5.5.0"
              },
              {
                "introduced": "4.6.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "d2ed0f7810e4f05a2fc6348286b622abf6464751"
            },
            {
              "fixed": "94dc72bba68fdb6e981abca35bafd315a7e776eb"
            }
          ],
          "repo": "https://github.com/vrana/adminer",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8478-xrj3-h9c2"
  ],
  "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"
  },
  "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.",
  "id": "CVE-2026-34959",
  "modified": "2026-08-28T11:30:52.622386292Z",
  "published": "2026-08-25T01:29:57.683Z",
  "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"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Adminer before 5.5.0 Open Redirect via X-Forwarded-Prefix"
}