Authentik
CVE-2026-40166
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V14 - Data Protection Data exposure prevention
MITRE ATT&CK
2 techniques across 2 tactics: Collection, Discovery The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
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Alert meAnalysisAIv1 – Jul 23, 2026
Sensitive information disclosure in authentik (goauthentik) before 2025.12.5 and in the 2026.2.0-rc1 through 2026.2.2 branch allows any authenticated low-privilege user holding at least one OAuth2 access token to read the client_secret of confidential OAuth2 providers they previously authenticated against. The GET /api/v3/oauth2/access_tokens/ endpoint over-returns a nested provider object containing client_id and client_secret, exposing credentials that should be restricted to administrators. No public exploit has been identified at time of analysis and EPSS is negligible (0.01%), but the flaw is a straightforward credential leak requiring only a normal user session.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
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
Primary rating from Vendor (GitHub_M) · only source for this CVE.
CVSS VectorVendor: GitHub_M
Lifecycle Timeline
3DescriptionCVE.org
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.
Executive ViewAI
Authentik versions before 2025.12.5 and 2026.2.0-rc1 through 2026.2.2 expose OAuth2 provider credentials (client_secret) to any authenticated user via the GET /api/v3/oauth2/access_tokens/ endpoint. Organizations using authentik for OAuth provider management risk credential compromise enabling service impersonation and unauthorized integrations into downstream systems.
Within 24 hours: Inventory all OAuth2 providers configured in authentik and audit downstream systems relying on their client credentials; restrict API access to /api/v3/oauth2/access_tokens/ endpoint to administrators only where possible. Within 7 days: Review authentik audit logs for suspicious access patterns to the vulnerable endpoint; rotate client_secrets for all OAuth2 providers as a precaution, documenting affected downstream systems. Within 30 days: Monitor the authentik project for vendor patch availability targeting versions 2025.12.5+ and 2026.2.3+; assess upgrade feasibility once a fix is released or evaluate whether to maintain compensating controls.
No vendor-released patch identified at time of analysis. Interim mitigations: restrict /api/v3/oauth2/access_tokens/ endpoint access to administrator roles via API authorization controls; rotate all OAuth2 client_secrets immediately; implement network segmentation to limit authentik access to authorized personnel; enable and monitor comprehensive audit logging for all token access; consider temporarily disabling unused OAuth2 providers pending vendor patch.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)CVE.org
authentik is an open-source identity provider. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploi
authentik is an open-source Identity Provider focused on flexibility and versatility. Rated high severity (CVSS 8.8), th
authentik is an open-source Identity provider focused on flexibility and versatility. Rated medium severity (CVSS 6.4),
Authentication bypass in authentik identity provider (versions prior to 2025.12.6, 2026.2.4, and 2026.5.1) allows remote
authentik is an open-source Identity Provider. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploi
authentik is an open-source Identity Provider. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploi
authentik is an open-source identity provider. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploi
authentik is an open-source identity provider. After authorizing access to a RAC endpoint, authentik creates a token whi
Account takeover in authentik (goauthentik) identity provider before 2026.2.6 and 2026.5.5 allows an attacker holding an
Cross-site scripting in authentik identity provider versions prior to 2025.12.5 and 2026.2.3 allows remote attackers to
Code injection in authentik identity provider from 2021.3.1 through multiple versions. Users with delegated permissions
authentik is an open-source identity provider. Rated critical severity (CVSS 9.0), this vulnerability is remotely exploi
Exploit-DB