In case you are the system admin and have access to the MediaWiki directory on the host, you can do the following
open a shell and enter the following commands:
cd path\to\your\mediawiki\maintenance php changePassword.php ––user="youruser" ––password="Your new password"
If you have no access, ask the admin to do so and change your password afterwords, of course.
-- Sent from: http://mediawiki-i.429.n8.nabble.com/