CVE-2025-71403: Better-Auth

High severity, CVSS 7.1. EPSS: 0.3% chance of exploitation in the next 30 days.

better-auth versions before 1.1.20 contain a bypass vulnerability in trustedOrigins validation logic affecting absolute URLs and wildcard domains. Attackers can construct malicious callbackURL parameters that pass origin checks and trigger open redirects to steal sensitive tokens for account takeover.

Affected products

• Better-Auth Better-Auth: before 1.1.20 (fixed in 1.1.20)

Published 2026-08-01. Last modified 2026-10-06.