Can a wall mounted data cabinet house a UPS?

It can hold a suitably sized UPS if both the cabinet and wall structure are rated for the fully installed weight. Sometimes it can mean adding an l-shaped support to the cabinet. The point is that UPS batteries (typically lead acid) are heavy, and so it is important to check the cabinet and wall loading limits. It is also important to check the depth and the wall type as you may need to use a suitable shelf or mounting kit, the wall may be plaster board or masonry.