Medium severity5.9OSV Advisory· Published Aug 2, 2026· Updated Sep 8, 2026
CVE-2025-71401
CVE-2025-71401
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
better-authnpm | < 1.4.2 | 1.4.2 |
Affected products
2v1.4.2-beta.1, v1.4.1, v1.4.0, …+ 1 more
- (no CPE)range: v1.4.2-beta.1, v1.4.1, v1.4.0, …
- (no CPE)range: <1.4.2
Patches
Vulnerability mechanics
References
6- github.com/advisories/GHSA-569q-mpph-wgwwghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2025-71401ghsaADVISORY
- github.com/better-auth/better-auth/releases/tag/v1.4.2ghsaWEB
- github.com/better-auth/better-auth/security/advisories/GHSA-569q-mpph-wgwwnvdWEB
- github.com/ray-project/ray/commit/70e7c72780bdec075dba6cad1afe0832772bfe09ghsaWEB
- www.vulncheck.com/advisories/better-auth-before-basepath-modification-dosnvdWEB
News mentions
1- Better Auth: 17 Vulnerabilities Disclosed Together, Including Critical Authorization Bypass FlawsVypr Intelligence · Aug 2, 2026