Poly Network Review 2026: Cross-Chain Bridge and the 2021 Hack

Poly Network is a cross-chain protocol that describes itself as infrastructure for blockchain interoperability. Its core function is moving tokens between blockchains, which is why it is classified as a bridge.

DefiLlama lists the protocol across more than 20 networks, from Ethereum and BNB Chain to Polygon, Avalanche and Arbitrum. The protocol does not have a native token listed on DefiLlama, and no total value locked figure is currently reported there.

The project is best known for an exploit in August 2021 in which attackers took roughly $600 million from its cross-chain contracts. Several reports say much of the money was later returned, which made the case unusual in the history of bridge attacks.

This review is based on public research and third-party write-ups rather than on hands-on use of the product.

A blockchain is a shared ledger that only records transactions on its own network. Tokens on one chain cannot be spent directly on another, so a bridge is used to move value between them.

In a typical lock-and-release design, a user deposits tokens into a contract on the source chain. The protocol then records that deposit and triggers the release of an equivalent amount on the destination chain. Poly Network describes itself as a protocol built for this kind of interoperability between chains.

Because the protocol holds locked assets and relies on cross-chain messages, its security depends on the contracts, the keys that control them, and the chains it connects. A failure in any of these can affect the transfer, which is why the 2021 exploit drew so much attention.

Fee terms are not published in the material this review draws on. Any cost you pay will usually include the gas fee on the source chain and on the destination chain, which depends on each network's congestion at the time of the transfer.

Check the fee breakdown shown before you confirm, and compare it with the amount you are sending, because small transfers can cost a meaningful share of their value.

Poly Network has two audits listed on DefiLlama. The audit reports and the firms behind them are not summarised in the material this review draws on, so check them directly before relying on them.

The protocol was the target of a large exploit in August 2021. One review site reports that its transactions run through a multisig wallet, which requires several approvals before funds move. A multisig setup reduces single-key risk but does not remove smart-contract risk.

The project does not publish regulatory status in the material this review draws on. Bridge users should understand that cross-chain transfers carry smart-contract, counterparty and chain-level risk. Online crypto services are for adults only (18+), and users should use only money they can afford to lose.

Poly Network is for experienced users and developers who need to move tokens between blockchains and who understand that bridges carry high risk. It is less suited to newcomers who have not yet learned how cross-chain transfers work.