A hacker exploited the Polkadot-based Hyperbridge cross-chain interoperability protocol, netting approximately $237,000 and raising renewed concerns about the security of blockchain bridge infrastructure.
According to blockchain, attacker minted 1 billion Bridged Polkadot tokens (DOT) in a single transaction on Hyperbridge data provided by the CertiK cybersecurity platform. The exploit only affected DOT on the Ethereum network, which was connected by a Hyperbridge, while DOT’s native tokens and the broader Polkadot ecosystem remained intact, Polkadot noted in Monday’s X post.
CertiK he said The hacker managed to mint the tokens after “slipping through a forged message designed to change the administrator of the Polkadot token contract on Ethereum.” Limited liquidity in the DOT pool circumscribed inflows to 108.2 Ether (ETH), worth approximately $237,000.
Hyperbridge Suspends Operations After Exploit
Hyperbridge paused operations after the attack while the team, along with collaborator Web3 Philosopher, worked on the update saying the initial diagnosis indicated a malicious piece of evidence that fooled the protocol’s Merkle tree verifier.
The exploit is notable because Hyperbridge did it introduced to the market itself as an evidence-based interoperability layer provide “full node security” for crosschain bridges. The incident also follows Aethir’s disclosure last week that it contained a separate bridge exploit and caused user losses to drop below $90,000.
Blocksec Falcon, a cybersecurity research company he said the likely cause of the exploit was a Merkle Mountain Range (MMR) mock replay vulnerability caused by evidence not being associated with the request, although the final root cause has not yet been confirmed by the protocol.
The native DOT token briefly dropped to an intraday low of $1.16 on Monday before recovering to above $1.19 at the time of writing, According to this CoinGecko.
Hackers exploit $130,000 SubQuery network
Security incidents continue to hit crypto protocols despite a piercing decline in losses related to DeFi exploits compared to the previous year.
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On Sunday, SubQuery Network’s data indexing protocol was also exploited for about $130,000 due to missing access control data that exposed code written more than two years ago.
The flaw allowed an attacker to set their own contract as the target for staking reward payouts, blockchain security auditor Pashov said in Sunday’s X post.
In the first quarter of 2026, hackers stole over $168 million from 34 decentralized finance (DeFi) protocols, a significant decline from the $1.58 billion stolen in the first quarter of 2025, which saw the record-breaking $1.4 billion Bybit hack.
Cointelegraph has reached out to Hyperbridge for comment on the root cause of the exploit.
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