On http://b2evolution.net/news/2006/05/17/b2evolution_0_9_2_sparkle_released, you see all the new things in 0.9.2
There also is a small download, with only changed files.
Take a look.

This version was for bug fixes and database ultimazations..

Yes, I have seen this. But I don't know which changes are the security changes. I don't want to implement all the changes. Is there an important security hole?

Well mark, you can't just half upload the changes..
that is for shure.

So or you do them all, or you don't do tham at all...

So, do I need to upgrade because there is a really huge security hole?

At my knowledge there is no securityhole.

The reason to upgrade is because your database whould love you for it.

But if you don't have a giant load of trafic, you can stay with your version..

It is still a 'stable' version.. so keep it.