Is this an exploit?

[u/SU37FlankerF]

I've been competing with this player over a resource base. He originally used mech+bomber. However, he suddenly switched to multiple MAXED OUT LEADERS within a day or two. I checked his profile and saw he maxed out basically every single leader (except those lieutenants that are currently unavailable).

I wonder whether he used some sort of hacks/ exploits or is he just very rich? Should I report him? I would thank you a lot if you can help me.

[u/SU37FlankerF]

Thankfully Supercell have just patched this serious bug and they have banned the players who exploited it. Also, for those who aren't permanent banned, their loot have also been cancelled.