How Does a “Governance Attack” Differ from a 51% Attack?

A governance attack targets the decision-making process of a blockchain, typically a decentralized autonomous organization (DAO), rather than the transaction ledger. It involves acquiring enough voting power (e.g. through holding a large number of governance tokens) to pass malicious proposals, such as draining the treasury or changing core protocol parameters.

A 51% attack is a technical manipulation of the ledger; a governance attack is a political/economic manipulation of the rules.