blueprintUE Self-Hosted Edition before 4.3.7 contains an insecure default configuration in its Docker Compose examples that sets MYSQL_ALLOW_EMPTY_PASSWORD=yes in database.env and publishes MariaDB on port 3306. Unauthenticated attackers reaching the Docker host on port 3306 can log in as root without a password to read, modify, or delete user accounts, blueprints, and all databases.