There has been a backport created for Cacti 0.8.8a for use in 12.0.4.
You can read the details about it in this Launchpad bug issue:Please backport cacti 0.8.8a-3 (universe) from quantal to precise
To upgrade your Cacti installation from 8.7i to 8.8a, perform the following commands from a terminal:
sudo add-apt-repository ppa:micahg/ppa
sudo apt-get install cacti
You should now be able to use the new Cacti Plugin Architecture.
The latest plugins can be downloaded from http://docs.cacti.net/plugins
In order to install the plugin, change to the directory where it was downloaded.
The default directory for cacti plugins is /usr/local/share/cacti/plugins/
Execute the following command:
sudo tar -xvf <insert-plugin-file-name-here>.tgz -C /usr/local/share/cacti/plugins/
The newly installed plugin should now be showing up in the cacti menu Console --> Plugin Management