UBB.threads PHP Forum Software Community Forums UBB.threads 7 Version 7 Support MySQL

First, make a backup of your existing database and then upgrade the database server.

There is a small downtime during the upgrade, so I would choose a time frame where your forum is not that busy.

cPanel recommend MariaDB 10.3 on the linked support page. I can also recommend that release. I am using MariaDB 10.3.12 here on my development server without any problems.