I'm not sure if there are any, considering previous versions of WP are vulnerable. Any reason why you want to use old versions of Wordpress or old themes? I know there have been many vulnerabilities with Wordpress in the past and would advise against using old versions of anything relating to Wordpress. It's one of the most common scripts that sites use, so it will have a huge aspect of vulnerability as every hacker will try to break the script! Sorry, if my response was not what you was looking for. Just food for thought!
I done did my research about wp2.6 vulnerability's. The reason is because my auto-blogging script is for that version and only that version.
http://www.binarymoon.co.uk/projects/regulus/ (Theme works for Wordpress 2.0 +) http://wp.smashingmagazine.com/2008/01/08/100-excellent-free-high-quality-wordpress-themes/ (100 free themes; article from 2008, so it should be compatible with WP-2.0+) I just typed in on Google, "Wordpress 2.0 themes" and managed to get a few good results from 2008... I assume the WP file pages haven't been updated; however you would have to test this for yourself! Good luck!