Ethereum Layer 2 Taiko Hacked, All Proposers Halt Block Production

Taiko is an Ethereum Layer 2 network that cuts costs by processing transactions off-chain before settling the results on Ethereum. Its cross-chain bridge transfers assets between the two chains. The attacker exploited flaws in the verification of chain-state and origin-signal proofs to forge withdrawal proofs, highlighting the security risks facing cross-chain infrastructure.

On June 22, 2026, Taiko instructed all proposers to stop producing new blocks and suspended its cross-chain bridge after an attacker drained about $1.7 million from bridge and token vaults on the Ethereum mainnet. After patching the vulnerability, completing an independent security review and replenishing reserves, the team fully reopened the bridge on July 2, restored 1:1 asset backing and compensated all affected users.