I don't see a problem for me posting this so here it goes...
Taken from v6.6 changelog :
May 2003: Version 6.6
=====================
- Added Associated Topics in News system (admin and user side)
- Fixed a XSS vulnerability present on mainfile.php for POST variables
- Fixed security bug in Your Account user's Information
- Fixed missing site name variable after rating a resource on Web Links module
- Fixed missing site name variable after rating a resource on Downloads module
- Fixed a bug on userinfo function in Your Account module
- Path disclosure bug fixed on Your Account module (Thanks to WB-Vortex from
http://www.winbeta.org)
- Path disclosure bug fixed on News module (Thanks to WB-Vortex from
http://www.winbeta.org)
- Path disclosure bug fixed on WebMail module (Thanks to WB-Vortex from
http://www.winbeta.org)
- Path disclosure bug fixed on Downloads module (Thanks to WB-Vortex from
http://www.winbeta.org)
- Path disclosure bug fixed on Web Links module (Thanks to WB-Vortex from
http://www.winbeta.org)
- Added Security graphic check in the user's login block
- Fixed custom name module creation when a new module is added and has underscore character
- Fixed default language bug when creating a new user
note: seems to me the secFix pack from nukecops listed more fixes than this.