How Does a 51% Attack Compromise the Security of a Token on a PoW Network?

A 51% attack occurs when a single entity controls more than half of the network's total mining hash rate. With this control, the attacker can selectively exclude or reorder transactions, and most critically, perform a double-spend.

For a token, this means the attacker could spend their tokens and then use their control to reverse the transaction, effectively stealing funds.