CVE-2026-33544
HIGH
MEDIUM
Priority: 0.03
BB Relevance:
45/100
Published: 2026-04-02
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Network
Conf. Impact
Integ. Impact
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
Low
UI:
Required
S:
Changed
C:
High
I:
High
A:
None
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.
Weakness Classification (1)
References & Advisories (3)
Product
Release Notes
Patch
Exploit
Mitigation
Vendor Advisory