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.
Published: 2026-08-02
Score: 9.3 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Sun, 02 Aug 2026 12:45:00 +0000

Type Values Removed Values Added
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.
Title better-auth before 1.4.1 basePath Modification DoS
First Time appeared Better-auth
Better-auth better-auth\/oauth-provider
Weaknesses CWE-770
CPEs cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:*
Vendors & Products Better-auth
Better-auth better-auth\/oauth-provider
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Better-auth Better-auth\/oauth-provider
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-02T12:19:23.688Z

Reserved: 2026-07-18T12:38:41.077Z

Link: CVE-2025-71401

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling