{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2026.2.0-rc1"
              },
              {
                "fixed": "2026.2.2"
              }
            ],
            "source": "DESCRIPTION"
          },
          "events": [
            {
              "introduced": "3394c17bfd5e208f8e8d53e450158e486afe575b"
            },
            {
              "fixed": "5249546862986202b901c2afd860992ec48c6ef6"
            }
          ],
          "repo": "https://github.com/goauthentik/authentik",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-hhpc-rqgm-pxj4"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-200",
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40166.json"
  },
  "details": "authentik is an open-source identity provider. In versions prior to 2025.12.5 and 2026.2.0-rc1 through 2026.2.2, authenticated non-admin users with at least one OAuth2 access token can retrieve the client_secret of confidential OAuth2 providers they have previously authenticated against, exposing sensitive information to users without the correct permissions. This logic is GET /api/v3/oauth2/access_tokens/. The API response includes a nested provider object containing client_id and client_secret for providers configured with client_type: confidential, which should not be accessible to low-privilege users. This issue has been fixed in versions 2025.12.5 and 2026.2.3.",
  "id": "CVE-2026-40166",
  "modified": "2026-07-15T01:49:21.337292336Z",
  "published": "2026-05-22T18:52:46.650Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40166.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40166"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/"
}