Security questions resurfaced across crypto markets after the recent polkadot hack incident on Hyperbridge’s Ethereum gateway, prompting an official response from the network’s team.
Polkadot clarifies impact of Hyperbridge exploit
On April 13, 2026, Polkadot issued a public statement addressing a security incident affecting the Ethereum gateway contract used by Hyperbridge. The project confirmed that only bridged DOT on Ethereum had been compromised, while core network assets remained intact.
The team stated, “We are aware of an issue affecting Hyperbridge’s Ethereum gateway contract.” However, the update stressed that the issue was limited in scope and did not extend to the entire Polkadot network or its relay chain.
Moreover, Polkadot emphasized, “The exploit only affects DOT on Ethereum that is bridged through Hyperbridge and does not affect DOT in the Polkadot ecosystem, or DOT bridged through other bridges.” This clarification aimed to draw a clear line between affected tokens and native assets.
Thus, the event did not impact native DOT on the relay chain, parachains, or other ecosystems connected to Polkadot. However, market sentiment still turned negative. The DOT price fell by 4.77% to $1.16 at press time, underlining a clear dot price drop linked to the security scare.
Hyperbridge pauses operations and reveals loss figures
As a precaution, bridging services tied to the compromised contract were immediately suspended. Polkadot noted that “Hyperbridge has been paused while the issue is investigated,” signaling an urgent move to contain potential further damage.
Moreover, Hyperbridge released a detailed incident report explaining the exploit and its consequences. It stated, “On April 13, 2026, a vulnerability in Hyperbridge’s Token Gateway was exploited, resulting in approximately $237,000 in losses on Ethereum.” This figure represents the direct financial impact identified so far.
The platform stressed that many cross-chain systems today rely on validator sets or multisignature approvals. However, such designs introduce structural trust assumptions that can be abused. Hyperbridge noted that these models have collectively contributed to more than $2 billion in cumulative bridge losses across the industry.
That said, the project argued that its own architecture was designed to lower these cross chain security risks by favoring cryptographic proofs from the underlying blockchain, instead of relying on centralized groups of human or institutional approvers.
Inside the Merkle Mountain Range verification bug
Hyperbridge explained that its system attempts to reduce bridge token forgery threats by anchoring security in cryptographic verification. However, the report makes it clear that the exploit did not stem from a conceptual failure of its cryptographic approach.
Instead, the probe found that the root cause was a proof forgery pathway in Hyperbridge’s implementation. Specifically, a bug was discovered in the Solidity-based Merkle Mountain Range proof verification logic used by the Ethereum gateway contract.
According to the report, this merkle mountain range bug emerged in the Merkle tree verifier implementation that attempted to mirror upstream Polkadot logic. However, the flaw led the system to treat certain invalid proofs as valid, breaking the intended security guarantees.
It was this verification failure that enabled a malicious message to slip past security checks. As a result, the attacker effectively gained administrative-level control over the bridged DOT token contract on Ethereum, opening the door to extensive token creation.
How the forged 1 billion bridged DOT was created and dumped
Once the attacker held this elevated access, they proceeded with what investigators describe as bridged dot minting on a massive scale. The exploiter minted 1 billion bridged DOT tokens, leveraging the compromised contract to bypass normal issuance limits.
This newly created supply dwarfed the legitimate circulating bridged DOT on Ethereum, which stood at approximately 356,000 tokens. In numerical terms, the fake issuance exceeded the real circulating supply by more than 2,800 times, highlighting the severity of the ethereum bridge vulnerability.
However, the attacker did not hold the position for long. The report notes that the forged tokens were rapidly moved into decentralized exchanges and similar trading venues. There, they were sold into the market, converting the exploit into liquid funds.
In its communication, Polkadot framed the event as a serious third-party infrastructure failure, rather than a failure of the core network itself. Nevertheless, the polkadot hack has reignited debate over the fragility of bridge architectures and their role in cross-chain interoperability.
Ongoing investigation and next steps
Furthermore, Hyperbridge confirmed that it is working closely with its security partners to trace the movement of the stolen funds on-chain. The team is also evaluating potential recovery avenues and mitigation strategies to address the financial damage.
Hyperbridge pledged to share further hyperbridge exploit details as the investigation continues and as new evidence is uncovered. However, no concrete timeline has been provided for the full reopening of bridge services or for any restitution process.
For now, bridging via Hyperbridge remains halted while technical teams review the Merkle proof implementation, contract logic, and monitoring systems. This pause aims to ensure that similar proof forgery vectors cannot be exploited again through the same pathway.
In summary, the incident exposed a critical weakness in one Ethereum-facing component of the Polkadot ecosystem, leading to a $237,000 loss and a short-term hit to market confidence. However, native DOT, parachains, and the relay chain infrastructure were not breached, underscoring that the core protocol security model remains intact despite the Hyperbridge failure.
Source: https://en.cryptonomist.ch/2026/04/14/polkadot-hack-hyperbridge-1b-dot/
