I would like to post a current exploit I found in version 4.6. A dup bug. No clue where else to post this.
In the current public version, when ever using right click in a follower to move the item to your inventory, or to consume the item, the item isn't being removed from the follower's inventory, leading to a very easy method of duplicating any item or endlessly using any potion effect. While it would be a fun cheat, it's still an exploit.
A similar dup bug exists currently in anvils, where if you right click any item in the anvil, you can draw from your inventory more of that item, even if that item has been exhausted from your inventory, you can still insert more of that item, such as salvage.