Just a quick post . Just days after WordPress 2.8.1 has been released , WordPress decided to release WordPress 2.8.2 and This is what is shown in their blog :
WordPress 2.8.2 fixes an XSS vulnerability. Comment author URLs were not fully sanitized when displayed in the admin. This could be exploited to redirect you away from the admin to another site. Download 2.8.2 or automatically upgrade from the Tools->Upgrade page of your blog’s admin.
So if you use WordPress 2.8.1 better upgrade it to WordPress 2.8.2.