CVE-2026-33544

7.7 HIGH
Published: April 02, 2026 Modified: April 07, 2026
View on NVD

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.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/steveiliop56/tinyauth/releases/tag/v5.0.5
Source: security-advisories@github.com
Product Release Notes
https://github.com/steveiliop56/tinyauth/security/advisories/GHSA-9q5m-jfc4-wc92
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.7 / 10.0
EPSS (Exploit Probability)
0.0%
14th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

tinyauth