CVE-2026-33544

Published: Apr 2, 2026Modified: Apr 7, 2026

7.7

Vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

Exploitability: 1.3 / Impact: 5.8

Source: security-advisories@github.com (Secondary)

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.

Affected (1)

Products: Tinyauth: Tinyauth

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Tinyauth Tinyauth	Before 5.0.5

Related CWEs

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

References (3)

https://github.com/steveiliop56/tinyauth/commit/f26c2171610d5c2dfbba2edb6ccd39490e349803

Source: security-advisories@github.com

Patch

https://github.com/steveiliop56/tinyauth/releases/tag/v5.0.5

Source: security-advisories@github.com

ProductRelease Notes

https://github.com/steveiliop56/tinyauth/security/advisories/GHSA-9q5m-jfc4-wc92

Source: security-advisories@github.com

ExploitMitigationVendor Advisory

Timeline

No history available yet.