CVE-2026-40166

Summary

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 Software

Weaknesses

• CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
• CWE-863: CWE-863: Incorrect Authorization

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

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

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