Ethereum Layer 2 network Taiko has halted block production across all proposers. In a post on X, the team said the pause was put in place while it investigates and fixes the issue. For now, new transactions on Taiko cannot be packaged into fresh blocks.
The shutdown followed a series of security alerts within a few hours. At 08:04 on June 22, security firm Blockaid reported that an ERC20 vault on Ethereum tied to Taiko had been attacked, with losses of more than $1 million. Its initial assessment pointed to a flaw in the proof verification logic for Taiko’s bridge source-signal mechanism. Later, at 09:48, PeckShield said the attacker had transferred 1.99 million TAIKO to MEXC, worth about $189,000 at the time.
Verification breach breaks bridge security assumptions
Taiko then confirmed that its chain state verification mechanism had been compromised. The project said the security assumptions behind bridges deployed on Taiko could no longer be treated as reliable. By 11:31, it announced that all proposers had stopped producing new blocks. That move freezes the normal flow of state updates and creates delays for applications that depend on current onchain data.
Bridges are seeing the most immediate disruption. Transfers between Ethereum and Taiko have been suspended, while data updates tied to DeFi pricing and NFT transfers are also expected to lag. Taiko is not the busiest Layer 2 network by traffic, but it already supports multiple DeFi protocols and bridge deployments, so the impact extends beyond a single application or contract.
Why a proposer halt affects the whole L2
Taiko describes itself as a Type-1 zkEVM built to remain fully EVM-equivalent with Ethereum mainnet. Its design relies on proposers to batch transactions, generate zero-knowledge proofs, and submit them to Ethereum for verification. Once all proposers stop, new transactions cannot move through that batching process, and the proof pipeline stalls with them. This is not a minor delay in one corner of the network. It is a pause at the block production layer.
According to the source material, Taiko is coordinating with its security council and ecosystem partners to contain the incident and has also taken technical and legal action to trace the attacker. The team has not published a timeline for restoring block production.