{"id":"CVE-2026-40166","summary":"authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/","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.","aliases":["BIT-authentik-2026-40166","GHSA-hhpc-rqgm-pxj4"],"modified":"2026-07-08T08:26:30.016195630Z","published":"2026-05-22T18:52:46.650Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40166.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-200","CWE-863"]},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/goauthentik/authentik","events":[{"introduced":"3394c17bfd5e208f8e8d53e450158e486afe575b"},{"fixed":"5249546862986202b901c2afd860992ec48c6ef6"}],"database_specific":{"extracted_events":[{"introduced":"2026.2.0-rc1"},{"fixed":"2026.2.2"}],"source":"DESCRIPTION"}}],"versions":["version/2026.2.2-rc3","version/2026.2.2-rc2","version/2026.2.2-rc1","version/2026.2.1","version/2026.2.1-rc1","version/2026.2.0","version/2026.2.0-rc5","version/2026.2.0-rc4","version/2026.2.0-rc3","version/2026.2.0-rc2","version/2026.2.0-rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40166.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","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"}]}