Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Coolify versions prior to and including v4.0.0-beta.420.8 have an information disclosure vulnerability in the "/api/v1/teams/{team_id}/members" and "/api/v1/teams/current/members" API endpoints allows authenticated team members to access a highly sensitive "email_change_code" from other users on the same team. This code is intended for a single-use email change verification and should be kept secret. Its exposure could enable a malicious actor to perform an unauthorized email address change on behalf of the victim. As of time of publication, no known patched versions exist.