Improper Authorization Affecting better-auth package, versions >=1.6.0 <1.6.11
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- published5 Jun 2026
- disclosed4 Jun 2026
- creditQuikturn Security Team
Introduced: 4 Jun 2026
CVE-2026-45337 (opens in a new tab)How to fix?
Upgrade better-auth to version 1.6.11 or higher.
Overview
better-auth is a The most comprehensive authentication library for TypeScript.
Affected versions of this package are vulnerable to Improper Authorization in the deviceAuthorization plugin. An attacker can gain unauthorized access to a device or deny legitimate user sign-in by submitting a valid user_code from any authenticated session before the legitimate user completes verification.
Note:
This is only exploitable if the deviceAuthorization plugin is enabled and a third party can observe a pending user code before the legitimate user completes verification.
Workaround
This vulnerability can be mitigated by disabling the plugin if device flow is not used, adding a before hook on POST /device/approve and POST /device/deny to enforce session ownership, or shortening the pending lifetime of device codes via the expiresIn plugin option.