All Joomla!® users need to patch their installations due to a vulnerability discovered on Dec. 14, 2105.
To resolve this error, you need to find out which version of Joomla! you have, and then patch it.
Your Joomla version number displays in the bottom-right corner.
How you patch Joomla! depends on which version you have:
To resolve this issue, you need to update your Website to version 3.4.6.
You will receive a confirmation once the update completes:
To resolve this issue, you need to replace the following file:
|Version||Link to download patched file|
session.phpfile from your local machine to
your Joomla! install directory\libraries\joomla\session\session.php.