Why Did Hyperbridge’s Loss Estimate Jump So Sharply?

Hyperbridge has revised the estimated impact of its April 13 Token Gateway exploit to about $2.5 million, up sharply from the initial $237,000 figure that reflected only early visible losses on Ethereum. The updated number, disclosed in a follow-up statement, captures damage traced across Base, BNB Chain, and Arbitrum in addition to Ethereum.

The change matters because the first estimate covered immediate token outflows, while the revised figure includes broader downstream damage to liquidity incentive pools where bridged DOT had been deployed. In practice, the incident was not limited to a single contract breach. It spilled into a multichain liquidity network that Hyperbridge had been actively building out through incentive programs.

The exploit unfolded in two stages. First, the attacker extracted about 245 ETH, which formed the basis of the early loss estimate. The more damaging phase came later, when the attacker gained control of the bridged DOT contract on Ethereum, minted about 1 billion units of bridged DOT, and dumped them into the market. That selloff appears to have distorted pool balances and drained value from liquidity providers across several chains.

What Broke Inside the Token Gateway?

The attack targeted the Token Gateway, a core part of Hyperbridge’s architecture that handles cross-chain transfers by locking or burning assets on one chain and minting or unlocking them on another. According to the project, the attacker exploited a flaw tied to the verification of Merkle Mountain Range proofs, allowing a forged message to pass as valid.

Hyperbridge said the problem stemmed from its Solidity-based verifier, where a key proof validation condition was not properly enforced. That failure let the attacker submit an invalid proof that the system accepted, effectively granting unauthorized administrative control over the bridged DOT contract on Ethereum. Security firm BlockSec independently identified the same failure point.

This is an important distinction. The breach did not come from a stolen key, compromised multisig, or operational breakdown. It came from the verification logic itself. That shifts the weakness from human or governance failure to protocol correctness, which is far more central to Hyperbridge’s claim of being a proof-based interoperability system.

Investor Takeaway

The exploit hit the part of Hyperbridge that is supposed to provide its security edge. That makes the incident more damaging than a routine bridge hack because it cuts directly into confidence around the protocol’s verification model.

Why Do the Liquidity Pool Losses Matter More Than the Initial Theft?

The broader financial damage is tied to Hyperbridge’s liquidity expansion strategy. In August 2025, the project launched a rewards campaign distributing 795,000 DOT to support bridged asset liquidity across Ethereum, Base, Arbitrum, and BNB Chain. Those same ecosystems are now identified as the main areas where incentive pool losses occurred.

That means the exploit did not just drain value from a single market on Ethereum. It disrupted a cross-chain network that had been seeded with incentives to deepen liquidity and support wider adoption of bridged DOT. Once the attacker minted and sold a massive amount of counterfeit bridged DOT, the impact spread through pools that were designed to support trading and settlement across multiple chains.

Investor Takeaway

Bridged asset failures can spread far beyond the hacked contract itself. Once a wrapped token is widely used in multichain liquidity pools, a mint exploit can quickly turn into a broader balance sheet event for liquidity providers and ecosystem incentives.

What Does This Mean for Hyperbridge’s Recovery and Market Standing?

Hyperbridge has paused the Token Gateway indefinitely and said it will not reactivate the system until the bug is patched and new contracts undergo another independent audit. The team is also working with centralized exchanges and compliance partners, including Binance, to trace and potentially recover funds, while law enforcement has been brought into the investigation.

If recovery efforts fail, the project has said affected users may be compensated with its native BRIDGE token after a one-year period. That introduces a different layer of risk. Rather than closing the loss quickly, part of the damage could be pushed into a future token-based compensation plan, creating a longer overhang around dilution, recovery credibility, and user confidence.

Matan Hamilis, co-founder and CTO of Sodot, pointed directly to a failure in the verification layer rather than a typical bridge breach, stating that “the attacker actually forged a fake ISMP state proof… that tricked the bridge’s verification logic into thinking a legitimate cross-chain message had come through.”

He explained that this single step allowed the attacker to take control of the system, noting that the forged message “reassigned admin control of the bridged DOT token contract on Ethereum to the attacker’s own contract,” effectively handing over minting authority.

He stressed that the impact was isolated to the wrapped asset rather than the underlying network. “Native DOT on Polkadot’s own relay chain was never touched,” he said, adding that “this was purely an Ethereum-side wrapped token problem.”

Hamilis also suggested the damage may be contained to a specific segment of the ecosystem. “At this point it seems as if the damage is limited to the DOT token on that bridge,” he said, noting that “other applications going through Hyperbridge weren’t affected.”