Unable to establish a PHP session PHPMyAdmin error

Access Denied Unable to establish a PHP session. If you believe that this is in error or inadvertent, contact your system administrator and ask them to review your server settings.

That was the error seen on a phpmyadmin installation on one of my customer servers. It’s related to the phpMyAdmin sessions, which need to be written inside the /tmp directory to work properly.

What causes Access Denied Unable to establish a PHP session PHPMyAdmin error?

This phpmyadmin error is caused usually by wrong file or directory permissions, as well as wrong owner on the /tmp files at this path:


I’ve also seen this error on the general /tmp directory of some plain CentOS servers.

How can I fix it?

For cPanel or DirectAdmin users

Just make sure the directory has the user ownership, you can set the right owner for this file by running:

chown username.username /home/$username/tmp

And let’s make sure the permissions are set to 755, run this command:

chmod 755 /home/$username/tmp

For plain Linux servers (without control panel)

chmod 1777 /tmp

That’s all, your phpmyadmin error should be totally fixed now.

About the Author: Martin Keler


  1. Using permissions of 777 is never a good idea or recommendation. Instead, you should suggest adjusting permissions accordingly to the requirements. There is never need to have permissions more open than 775 at most…

    1. I agree about 777 is insecure, however, if you check the guide you will notice it is 1777, not 777.

      1 before 777 means only the owner of the file (root in this case) can modify the directory or file (in this case, the /tmp partition).

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