CVE-2026-77561
mediumTinyauth is an authentication and authorization server.
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/tinyauthapp/tinyauth/commit/654b5cc436fc67865c1f55edf9ba9fbded50b74f security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/commit/dade1e2c8f27a23df56ac216dcaf4b37081698e7 security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/pull/1008 security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/pull/943 security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/releases/tag/v5.1.0 security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh security-advisories@github.com
- https://github.com/tinyauthapp/tinyauth/security/advisories/GHSA-9xhm-w3wj-xhqh 134c704f-9b21-4f2e-91b3-4a467353bcc0