Vulnerability Description
Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct fields on singleton instances shared across all concurrent requests. When two users initiate OAuth login for the same provider concurrently, a race condition between VerifyCode() and Userinfo() causes one user to receive a session with the other user's identity. This issue has been patched in version 5.0.5.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Tinyauth | Tinyauth | < 5.0.5 |
Related Weaknesses (CWE)
References
- https://github.com/steveiliop56/tinyauth/commit/f26c2171610d5c2dfbba2edb6ccd3949Patch
- https://github.com/steveiliop56/tinyauth/releases/tag/v5.0.5ProductRelease Notes
- https://github.com/steveiliop56/tinyauth/security/advisories/GHSA-9q5m-jfc4-wc92ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-33544?
CVE-2026-33544 is a vulnerability with a CVSS score of 7.7 (HIGH). Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifie...
How severe is CVE-2026-33544?
CVE-2026-33544 has been rated HIGH with a CVSS base score of 7.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-33544?
Check the references section above for vendor advisories and patch information. Affected products include: Tinyauth Tinyauth.