This image has not been officially confirmed, but it looks like the real deal to me. With only 5 months to go until the release of “Solo”, we should be getting some promotional material and this could be the first one. This originally was posted on reddit and the image originates somewhere from Russia, as you can see by the writing in the main title. In this image we see Chewbacca (Joonas Suotamo), Han Solo (Alden Ehrenreich), Lando Calrisian (Donald Glover) and Kira (Emilia Clarke).
And another potential image has also leaked. Seems to be the reverse image of the above image plus the addition of The Millennium Falcon.