Better Auth allows bypassing the trustedOrigins Protection which leads to ATO

Summary

A bypass was discovered in the trustedOrigins validation logic—affecting both absolute URL entries and wildcard domain patterns. This flaw allows an attacker to construct a malicious callbackURL that passes origin checks and triggers an open redirect.

Because redirect endpoints include sensitive tokens (such as password-reset tokens), this vulnerability can enable one-click account takeover if a victim clicks a crafted link.