I'm unsure whether this has already been discovered, but whatever - if you jump while sneaking, and hit 'Lb' in my case, being on xbox, as you would to sprint or roll in sneak, you can sneak roll before it is unlocked as an ability.
Has anyone else encountered this?
Sorry, I'm late to the party if it's been picked up.

Thanks, I'll try it but not sure what use it's for?

Are you sure it is not just a Roll?

This move can be used to get under swinging blades in dungeons and I have seen Lydia, not a Sneak skilled person at all, do this move. I have never tried it as I had other ways, like Ethereal to get past them.