{"id":"CVE-2026-40166","state":"PUBLISHED","title":"authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/","description":"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.","publishedAt":"2026-05-22T18:52:46.650Z","updatedAt":"2026-05-26T18:47:57.418Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["goauthentik authentik"],"affected":[{"vendor":"goauthentik","product":"authentik","versions":[{"version":"< 2025.12.5","status":"affected"},{"version":">= 2026.2.0-rc1, < 2026.2.3","status":"affected"}]}],"references":["https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4","https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5","https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3"],"weaknesses":["CWE-200","CWE-863"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40166.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40166","state":"PUBLISHED","datePublished":"2026-05-22T18:52:46.650Z","dateUpdated":"2026-05-26T18:47:57.418Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-09T19:31:56.014Z"},"containers":{"cna":{"title":"authentik: Non-admin user can retrieve confidential OAuth client_secret via /api/v3/oauth2/access_tokens/","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"goauthentik","product":"authentik","versions":[{"version":"< 2025.12.5","status":"affected"},{"version":">= 2026.2.0-rc1, < 2026.2.3","status":"affected"}]}],"references":[{"url":"https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4","name":"https://github.com/goauthentik/authentik/security/advisories/GHSA-hhpc-rqgm-pxj4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5","name":"https://github.com/goauthentik/authentik/releases/tag/version%2F2025.12.5","tags":["x_refsource_MISC"]},{"url":"https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3","name":"https://github.com/goauthentik/authentik/releases/tag/version%2F2026.2.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","lang":"en","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-22T18:52:46.650Z"},"source":{"advisory":"GHSA-hhpc-rqgm-pxj4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-26T18:47:45.180359Z","id":"CVE-2026-40166","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-26T18:47:57.418Z"}}]}}}