CVE-2026-33544 | steveiliop56 tinyauth up to 5.0.4 GenericOAuthService VerifyCode race condition (GHSA-9q5m-jfc4-wc92)

VDB-354890 · CVE-2026-33544 · GHSA-9Q5M-JFC4-WC92 STEVEILIOP56 TINYAUTH UP TO 5.0.4 GENERICOAUTHSERVICE VERIFYCODE RACE CONDITION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.1 $0-$5k 0.25+ Summaryinfo A vulnerability was found in steveiliop56 tinyauth up to 5.0.4 and classified as problematic. This affects the function VerifyCode of the component GenericOAuthService/GithubOAuthService/GoogleOAuthService. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2026-33544. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component. Detailsinfo A vulnerability, which was classified as problematic, has been found in steveiliop56 tinyauth up to 5.0.4. Affected by this issue is the function VerifyCode of the component GenericOAuthService/GithubOAuthService/GoogleOAuthService. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. 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. Impacted is confidentiality, integrity, and availability. CVE summarizes: 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. The advisory is available at github.com. This vulnerability is handled as CVE-2026-33544 since 03/20/2026. The exploitation is known to be difficult. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. Upgrading to version 5.0.5 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch f26c2171610d5c2dfbba2edb6ccd39490e349803 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Vendor steveiliop56 Name tinyauth Version 5.0.0 5.0.1 5.0.2 5.0.3 5.0.4 License open-source Website Product: https://github.com/steveiliop56/tinyauth/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 6.1 VulDB Meta Temp Score: 6.1 VulDB Base Score: 4.6 VulDB Temp Score: 4.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 7.7 CNA Vector (GitHub_M): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Race condition CWE: CWE-362 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: tinyauth 5.0.5 Patch: f26c2171610d5c2dfbba2edb6ccd39490e349803 Timelineinfo 03/20/2026 CVE reserved 04/02/2026 +12 days Advisory disclosed 04/02/2026 +0 days VulDB entry created 04/02/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: GHSA-9q5m-jfc4-wc92 Status: Confirmed CVE: CVE-2026-33544 (🔒) GCVE (CVE): GCVE-0-2026-33544 GCVE (VulDB): GCVE-100-354890 Entryinfo Created: 04/02/2026 17:25 Changes: 04/02/2026 17:25 (68) Complete: 🔍 Cache ID: 99:5AA:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸