https://www.cnet.com/news/galaxy-s9-first-software-update/

The Samsung Galaxy S9 and Galaxy S9 Plus don't hit shelves until March 16, but the Galaxy S9's first software update is already rolling out.

A screenshot of the update prompt was shared on Reddit by ironkid65. From it, we can see the update's version number, and that it'll take up 260MB of space. We haven't tested the update, so we can't confirm everything that comes with it, but the update text says that the stability of the camera and Face Unlock have been improved.