Taiko Halts Its Ethereum Layer-2 After Forged Bridge Proofs Drain $1.7 Million

Taiko, an Ethereum layer-2 network, stopped producing blocks early on June 22 after an attacker forged bridge withdrawal proofs and drained roughly $1.7 million, according to CoinDesk. The team told users that every bridge deployed on the protocol should now be treated as unsafe and urged immediate withdrawals.

The mechanism is the recurring weakness in cross-chain infrastructure. A bridge releases funds on one chain when it receives proof that a corresponding deposit or message occurred on another. Taiko's contracts on Ethereum mainnet accepted forged message proofs that had no matching event on the Taiko chain, letting the attacker register fake bridge messages and pull tokens out of an ERC-20 vault, mostly in USD Coin (USDC) and ether. The root cause lies in the bridge's source-signal proof validation, The Block reported. The attacker also moved close to 2 million TAIKO tokens toward exchanges.

This is the same class of flaw, proof or signature verification that fails to confirm an event ever happened, behind major bridge drains this year. What differs here is the response time. By halting all block proposers within roughly an hour of the first signs on-chain, Taiko's operators limited the loss to the low millions of dollars rather than the hundreds of millions lost elsewhere. That containment is also a frank admission. A network that its core team can halt to stop a theft is not yet operating with the trust-minimized guarantees that the term layer-2 is meant to imply.

The incident comes during a difficult period for on-chain security. One widely shared count records roughly 70 separate hacks in the second quarter of 2026, about double the previous quarter, even though the total lost, near $746 million, remains below earlier peaks, according to crypto monitors. The pattern is more frequent exploits for smaller amounts, hitting an expanding range of bridges and second-layer systems.