CVE-2026-33544

Publication date

2026-04-02 15:00:38

Family

GitHub_M

State

PUBLISHED

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 users identity. This issue has been patched in version 5.0.5.