CVE-2026-33544

HIGH EPSS 25.6%
Published Apr 2, 20263mo ago · Modified Jun 17, 20262w ago
7.7 CVSS 3.1
High
Find Similar
Published Apr 2, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
7.7
Exploitability
1.3
Impact
5.8
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack Vector Network
Attack Complexity High
Privileges Required Low
User Interaction Required
Scope Changed
Confidentiality High
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
25.6% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-362

Affected Products 1

VendorProductVersionRange
tinyauthtinyauth* <5.0.5

References 3

  • github.com https://github.com/steveiliop56/tinyauth/commit/f26c2171610d5c2dfbba2edb6ccd39490e349803
    Patch
  • github.com https://github.com/steveiliop56/tinyauth/releases/tag/v5.0.5
    ProductRelease Notes
  • github.com https://github.com/steveiliop56/tinyauth/security/advisories/GHSA-9q5m-jfc4-wc92
    ExploitMitigationVendor Advisory

Remediation

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