Most sides a cube's shadow can have

A cube hangs in the air and a light projects its shadow onto a flat wall. You may orient the cube however you like. What is the greatest number of sides the shadow polygon can have?

$6$. A projection of a convex polyhedron is bounded by the projections of its silhouette edges. A cube shows at most three faces at once, and when three faces are visible the outline consists of $6$ edges, giving a hexagon (a regular one when viewed along a space diagonal).