The fourth and last maintenance update to Ubuntu 10.04 LTS Lucid Lynx, 10.04.4, is available for download with numerous security updates and bug fixes, covering server, desktop, alternate installation CD, DVD for i386 and amd64 architectures.
Ubuntu 10.04.4 is the last updated 10.04 LTS installation media, further security updates and bug fixes will be available, as usual, via Ubuntu archives until April 2013 on desktops and April 2015 on servers (starting with Ubuntu 12.04, the LTS will be supported five years on both desktop and server).
Download Ubuntu 10.04.4 desktop http://www.ubuntu.com/download/ubuntu/download
Download Ubuntu 10.04.4 server http://www.ubuntu.com/download/server/download
Various workarounds and official release notes are available on http://www.ubuntu.com/getubuntu/releasenotes/1004