CVE-2026-23478 Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback

Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update. This vulnerability is fixed in...