source: http://www.securityfocus.com/bid/11268/info

It is reported that Wordpress is affected by various cross-site scripting vulnerabilities. These issues are due to a failure of the application to properly sanitize user-supplied URI input. 

Wordpress 1.2 is reported vulnerable, however, other versions may be affected as well.

/wp-login.php?redirect_to=[XSS]
/wp-login.php?mode=bookmarklet&text=[XSS]
/wp-login.php?mode=bookmarklet&popupurl=[XSS]
/wp-login.php?mode=bookmarklet&popuptitle=[XSS]