I don't know if this qualifies as an exploit but it's certainly unexpected.
In Vvardenfell, Gnisis, the egg mine quest: the hole in the wall where the gears are spinning, my character seems to be short enough I can jump through the wall and outside the map. I spent a good 45 minutes running around looking for ways back into the map but didn't find anything. At first I thought this was intentional and I had landed on some strange land.
But as you can see from the Polaroids I took something's not quite right.