CVE-2026-67328

Name of the Vulnerable Software and Affected Versions @better-auth/sso versions prior to 1.6.21

Description Multiple authentication bypass issues exist in the handling of SSO providers, allowing attackers to sign in as arbitrary users. This can be achieved through domain verification parsing mismatches, orphaned provider accounts, or unbound SAML assertions. Additionally, reflected XSS (Cross-Site Scripting, a technique where malicious scripts are injected into trusted websites) on logout endpoints can be used to gain unauthorized session access and account takeover.

Recommendations Update @better-auth/sso to version 1.6.21 or later.