CVE-2026-77561

Tinyauth is an authentication and authorization server. Prior to 5.1.0, an unauthenticated remote attacker can send POST /api/user/login requests with 257 distinct nonexistent usernames to fill MaxLoginAttemptRecords and activate a global login lockdown. internal/controller/user_controller.go loginHandler passes each attacker-controlled identifier to internal/service/auth_service.go RecordLoginAttempt, which invokes lockdownMode after the map reaches its cap. IsAccountLocked checks that global state before validating unrelated accounts, causing valid users to receive HTTP 429 until auth.loginTimeout expires, approximately 300 seconds by default. The attack can be repeated, but existing authenticated sessions are not invalidated. This issue is fixed in version 5.1.0.
Configurations

No configuration.

History

24 Sep 2026, 23:19

Type Values Removed Values Added
References () https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh - () https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh -

21 Sep 2026, 17:18

Type Values Removed Values Added
New CVE

Information

Published : 2026-09-21 17:18

Updated : 2026-09-24 23:19


NVD link : CVE-2026-77561

Mitre link : CVE-2026-77561

CVE.ORG link : CVE-2026-77561


JSON object : View

Products Affected

No product.

CWE
CWE-307

Improper Restriction of Excessive Authentication Attempts