CVE-2026-67327: better-auth before 1.6.22 Account Takeover via Magic-Link Email-OTP

Severity: high (CVSS 8.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-01 · updated 2026-09-08
Weakness: CWE-287

Description

better-auth versions >= 1.1.3 and < 1.6.22 (and pre-release versions >= 1.7.0-beta.0 and < 1.7.0-beta.10) are vulnerable to account takeover via pre-account hijacking on magic-link and email-OTP sign-in when open email/password registration is enabled. An attacker registers an account with the victim's email address and an attacker-chosen password; the account remains unverified. When the legitimate owner later signs in via the magic-link or email-OTP passwordless flow, the account is marked verified without removing the pre-existing password or revoking existing sessions, so the attacker's password remains valid, granting persistent access to the victim's account. Fixed in 1.6.22 and 1.7.0-beta.10.

Affected products

better-auth: from 1.1.3 before 1.6.22; from 1.7.0-beta.0 before 1.7.0-beta.10 — fixed in 1.6.22, 1.7.0-beta.10

How to fix

Upgrade to a fixed version: better-auth 1.6.22, 1.7.0-beta.10. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-67327 or the next vulnerability affects your stack