A MySQL or MariaDB “Access denied” error usually means the connection credentials or privileges do not match what the server expects.

1. Verify the database name, database username, password, and host used by the application.
2. In cPanel Manage My Databases, confirm the database user exists.
3. Confirm that the user is assigned to the intended database with the privileges the application requires.
4. If the password was recently changed, update the application configuration to match.
5. Check whether the application is trying to connect remotely when the database is local, or vice versa.

Do not confuse the cPanel account password with a database-user password; they are separate credentials.