Harmony, the Layer-1 blockchain protocol, is weighing the potential rollback of its network after an attacker exploited a vulnerability and minted nearly 4 billion ONE tokens, representing about 26% of the coin’s total supply.
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AAPLImmediate response and ongoing investigation
On August 11, Harmony’s development team stated that it was working closely with cryptocurrency exchanges to identify, freeze, and block funds associated with the incident. The priority is to prevent further movement of the unauthorized tokens and to mitigate the fallout for existing holders.
Developers are crafting a patch to address the underlying vulnerability and are exploring the viability of restoring the blockchain to its state before the exploit. Harmony has not yet commented on the technical specifics, the total number of illicitly created tokens, or how many have already been transferred to exchanges.
The team’s announcement followed a detailed analysis posted by the X account Juiceberg, which suggested that attackers managed to mint unauthorized ONE tokens by exploiting empty blocks within the network.
According to Juiceberg, approximately 2.8 billion of the newly minted ONE were moved to exchanges soon after the incident, as the token’s price began to plummet.
Estimates from the same source indicate that the attacker may still control 115 million ONE on-chain, equating to roughly 2.9% of the exploit’s total haul. The remaining tokens could already have been sold or lodged within exchange deposit wallets.
These figures are yet to be independently verified, and Harmony has not provided a full breakdown of the affected supply or published a detailed post-mortem of the incident.
Mini dictionary: Harmony, a Layer-1 blockchain protocol, offers fast and scalable infrastructure for decentralized applications, focusing on low-latency and low-fee consensus.
Token price impact and dilution fears
The exploit triggered significant selling pressure on ONE, causing the token’s price to fall more than 50% at its lowest point. As of the latest update, ONE remains down roughly 33.6% over the past 24 hours.
| Metric | Before Exploit | After Exploit |
|---|---|---|
| ONE total supply | ~15.1 billion | ~19.1 billion |
| ONE circulating price drop | – | Down 33.6% |
The steep decline reflects the market’s uncertainty over a substantial and sudden increase in circulating supply, as well as concerns about potential intervention by network administrators and the precedent it could set for blockchain governance.
If billions of unauthorized tokens remain on the open market, the resulting dilution could continue to pressure ONE’s price. A possible rollback, meanwhile, raises questions about integrity, decentralization, and the permanence of blockchain transactions.
Previous attacks and outlook
The incident unfolds a little over two years after the high-profile Horizon Bridge hack in June 2022, which resulted in roughly $100 million in digital asset losses. That earlier attack was attributed by the FBI to the Lazarus Group, a cybercrime organization linked to North Korea.
This latest breach underlines continued security challenges for Harmony, following its prior experience as one of the most heavily impacted networks in the bridge exploit wave affecting several blockchains.
Harmony’s team is currently working with exchanges to restrict movement of the newly created tokens while they finalize a patch. Rollback scenarios are under evaluation, though the developers have not reached a decision.
Any proposal to reverse the blockchain state would likely require broad support from Harmony’s validators and the wider community to go forward.
Harmony is assessing whether billions of unauthorized ONE tokens, minted through a vulnerability, can be purged by rolling the network back. No final decision has been made and the outcome may depend on community consensus.
