It is a Movable Type Security Update.
Today we are releasing Movable Type 4.01b and Movable Type 4.12. These are free mandatory security updates for all Movable Type 4.x users.
Action now, upgrade your MT installation. It is a Security update.
I have some MT 4.1 installation on Dreamhost. I update them just two minutes ago.
It is simply and easy to update.
1) SSH to server.
2) wget http://www.movabletype.com/download/personal/MTP-4.12-en.tar.gz
3) tar -xvzf MTP-4.12-en.tar.gz
4) cp -r -f . ~/sitedir/mtcgi/
5) login MovableTyep and done.