CVE-2025-71401 Details
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.
A denial-of-service vulnerability has been identified in better-auth versions prior to 1.4.2. The issue arises because the application allows external requests to configure the baseURL when it is not otherwise defined. An attacker who can make the first request to the server after it starts up can poison the router's base path, leading all routes to return a 404 error for all users. This vulnerability is not present when the baseURL is explicitly set or on typical managed hosting platforms.
Users can upgrade to better-auth version 1.4.2 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Aug 2, 2026CISA-ADP
Assessed Aug 3, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-770 | Allocation of Resources Without Limits or Throttling | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| better-auth | < 1.4.1 (semver) |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 3, 2026 | CVE Modified | CISA-ADP |
| Aug 3, 2026 | CVE Modified | [email protected] |
| Aug 2, 2026 | New CVE Received | [email protected] |