Vulnerability Description
better-auth (npm) before 1.4.2 allows an external request to configure baseURL when it is not otherwise defined (e.g., BETTER_AUTH_URL is unset). An attacker able to make the very first request to the server after startup can poison the router's base path, causing all routes to return 404 for all users (denial of service). The issue is not reachable when baseURL is explicitly configured or on typical managed hosting platforms.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/better-auth/better-auth/security/advisories/GHSA-569q-mpph-wg
- https://www.vulncheck.com/advisories/better-auth-before-basepath-modification-do
FAQ
What is CVE-2025-71401?
CVE-2025-71401 is a vulnerability with a CVSS score of 5.9 (MEDIUM). better-auth (npm) before 1.4.2 allows an external request to configure baseURL when it is not otherwise defined (e.g., BETTER_AUTH_URL is unset). An attacker able to make the very first request to the...
How severe is CVE-2025-71401?
CVE-2025-71401 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-71401?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.