Item duplication: Building a C.A.M.P. next to a location with a storage box, placing items in the box, triggering a server disconnect, then reconnecting to the same server will those items to be retrieved and duplicated.
Unlimited carry weight: Repeatedly building new pieces of pocketed armor can cause max carry weight to become negative.
Unlocked items: Items that are not yet owned by the player can be created by the C.A.M.P. if the player is already able to create any variant of the item in that construction level. The player simply needs to place the item that can already be created, store it, and then go to the Stored tab and place it back down as a different variant. (Probably fixed by Fallout 76 patch 18.104.22.168)
Power armor duplication: Exiting the armor within a C.A.M.P. and disconnecting the network connection can duplicate the armor.
Camp duplication: Moving a C.A.M.P. while a server disconnect occurs can cause duplication of all items in the camp.
Infinite grenades and XP: The Home Defense perk can be used by the player to repeated disarm certain grenade traps to yield large numbers of fragmentation grenades and XP (fixed by Fallout 76 patch 22.214.171.124).
Item duplication: The artillery piece can be used to duplicate arbitrary items by placing them into the box of an artillery piece belonging to another player prior to that player logging out (possibly fixed by the service outage that followed Fallout 76 patch 126.96.36.199).
Infinite carry: Armor that have the "pocketed" attribute can be equipped and de-equipped very rapidly to gradually lower the player's carrying weight until it becomes negative, giving the player an unlimited carrying weight for the rest of that server session. (Probably fixed by Fallout 76 patch 188.8.131.52)
Extra rewards: In the Battle Bot public event quest, it is possible to rapidly press the final "master shutdown" button and receive the reward multiple times for completing the quest (Possibly fixed by Fallout 76 patch 184.108.40.206)