Fixes are described at
However, there’s a way to preserve the additional security provided by this unix_socket plugin. Instead of connecting via TCP/IP, connect via the socket.
The location of the socket file on Ubuntu is
/var/run/mysqld/mysqld.sock. Use this path in your connection settings in MySQL Workbench. Then, restart the application as root:
You run it as root, and it can then connect to the database, as a Unix root user, logging in as a database root user.
This won’t work across two computers, of course.