Why can a single compromised validator approve a $300M bridge withdrawal?

Omnichain messaging protocols let bridge deployers choose how many independent verifiers must sign a cross-chain message before funds move. In April 2026, KelpDAO lost $292M because their bridge ran with a single DVN, a configuration that every smart contract audit had cleared because the contract code itself was correct. The exploit did not require finding a code bug; it required compromising one off-chain operator and forging one message. No on-chain enforcement today prevents a bridge from going live with a 1-of-1 setup, and there is no audit standard that covers DVN configuration semantics rather than bytecode logic.