Authentication Bypass Using an Alternate Path or Channel Affecting better-auth package, versions <1.4.9


Severity

Recommended
0.0
critical
0
10

CVSS assessment by Snyk's Security Team. Learn more

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-JS-BETTERAUTH-15876756
  • published3 Apr 2026
  • disclosed3 Apr 2026
  • creditTriDecent

Introduced: 3 Apr 2026

New CVE NOT AVAILABLE CWE-288  (opens in a new tab)

How to fix?

Upgrade better-auth to version 1.4.9 or higher.

Overview

better-auth is a The most comprehensive authentication library for TypeScript.

Affected versions of this package are vulnerable to Authentication Bypass Using an Alternate Path or Channel in the session.cookieCache component. An attacker can gain unauthorized access to protected application routes by leveraging a session that is cached as valid before all authentication steps, such as two-factor authentication, are completed.

Note:

This is only exploitable if both two-factor authentication and session cookie caching are enabled.

Workaround

This vulnerability can be mitigated by disabling session.cookieCache when two-factor authentication is in use.

CVSS Base Scores

version 4.0
version 3.1