When configuring a local development environment (such as on a virtual machine or local development container) where MySQL root has an empty password, phpMyAdmin blocks authentication attempts by default with the following error:

Login without a password is forbidden by configuration (see AllowNoPassword)

This security safeguard prevents accidental deployment of passwordless database instances in publicly accessible environments.

Enabling Empty Passwords in config.inc.php

To enable passwordless authentication for local sandbox testing, modify the phpMyAdmin configuration file:

sudo nano /etc/phpmyadmin/config.inc.php

Locate the AllowNoPassword directive within the server connection settings block (around line 96 in standard Debian/Ubuntu installations):

/* $cfg['Servers'][$i]['AllowNoPassword'] = TRUE; */

Uncomment the line by removing the comment markers:

$cfg['Servers'][$i]['AllowNoPassword'] = TRUE;

Save the file and exit the editor. You can now authenticate immediately to phpMyAdmin using username root with the password field left empty.

[!CAUTION] Never enable AllowNoPassword on internet-facing servers or production infrastructure. Restrict this configuration exclusively to isolated local development sandboxes.