I’d recommend reading my post for information on reducing exploiting: How you should secure your game - A beginner guide for secure networking and developing anticheats
You should thoroughly make sure you don’t have any backdoors in your game from malicious or stolen plugins.
I also wrote this: GameTree - Malicious script/backdoor scanning tool
CFrames are specific to rotation/position of parts. Character’s can only manipulate their root part’s CFrame not their limb CFrames. Animations can also control this and that would be my best guess if you are 100% sure you have no backdoors.