not sure if its a bug but it ruins the experience for me and maybe other users
in hardcore if you press open to LAN and enable cheats you can have cheats in hardcore
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Hello!
Please see MC-134; this has been marked as working as intended. You can suggest a change to this at http://feedback.minecraft.net if you'd like!
This is not a bug, it is a real feature to enable cheats no matter hardcore or vanilla. You are requesting a feature of no activate cheats in hardcore. Please do that on MC suggestions website!