Insufficient Verification of Data Authenticity Affecting better-auth package, versions >=1.1.3 <1.6.22>=1.7.0-beta.0 <1.7.0-beta.10
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published26 Jul 2026
- disclosed24 Jul 2026
- creditVercel Security Team
Introduced: 24 Jul 2026
NewCVE-2026-67327 (opens in a new tab)How to fix?
Upgrade better-auth to version 1.6.22, 1.7.0-beta.10 or higher.
Overview
better-auth is a The most comprehensive authentication library for TypeScript.
Affected versions of this package are vulnerable to Insufficient Verification of Data Authenticity in the authentication process. An attacker can gain persistent unauthorized access to user accounts by registering an account with a victim's email address and a chosen password before the victim signs in using passwordless methods. When the victim later signs in via magic-link or email-OTP, the attacker's password remains valid, allowing continued access and potential takeover of the account. This is only exploitable if both the magic-link or email-OTP plugin and open email/password registration are enabled, and an account can be created for an email address before the legitimate owner signs in with the passwordless flow.
Workaround
This vulnerability can be mitigated by requiring email verification before accepting any password on an account and by promptly removing unverified accounts.