5.9
MEDIUM CVSS 4.0
CVE-2025-71401
better-auth before 1.4.1 basePath Modification DoS
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.

INFO

Published Date :

Aug. 2, 2026, 1:16 p.m.

Last Modified :

Aug. 2, 2026, 1:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-71401 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update better-auth to 1.4.2 or later to fix the external configuration vulnerability.
  • Update the better-auth npm package.
  • Ensure baseURL is explicitly configured.
  • Apply vendor patches or updates promptly.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-71401.

URL Resource
https://github.com/better-auth/better-auth/security/advisories/GHSA-569q-mpph-wgww
https://www.vulncheck.com/advisories/better-auth-before-basepath-modification-dos
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-71401 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-71401 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-71401 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 02, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'better-auth', 'product': 'better-auth', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.4.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '1.4.1', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/better-auth', 'defaultStatus': 'unaffected'}]
    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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-770
    Added Reference https://github.com/better-auth/better-auth/security/advisories/GHSA-569q-mpph-wgww
    Added Reference https://www.vulncheck.com/advisories/better-auth-before-basepath-modification-dos
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.