Yes that means all versions including the current version and before, 2.0.4 has not yet been released at the current time.
An exploit has been discovered in the current release of WordPress, affecting WordPress 2.0.3 and below (including 1.5.x) that allows these subscribed users to cause some serious damage.
It’s recommended at present if you are using WordPress to disable the “Anyone can Register” option in your ‘Options’ tab.
It’s also advised you delete any unknown subscribers that haven’t commented or that you don’t know personally.
WordPress developers are aware of this flaw and hopefully it will be fixed in the 2.0.4 release which is imminent.
Leaving it open and letting people sign-up for guest accounts on your WordPress blog could lead to incredibly nasty stuff happening if anybody so desired. And trust me I am not exaggerating this. So don’t wait a second to disable this option and please relay the message.
WordPress dev team has been notified a while back and I dare hope they will soon start acting on it, if only by relaying a similar announcement through the official channel (as well as, of course, releasing a proper patch).
Source: Dr Dave