A potential rollback of the Harmony blockchain is under consideration following allegations that an attacker exploited the network, resulting in the creation of nearly 4 billion new ONE tokens. This massive unauthorized mint represents approximately 26% of the cryptocurrency's total supply.

In response to the situation, the team behind the layer-1 blockchain announced on Tuesday that it is collaborating with exchanges to halt and secure the funds. Additionally, Harmony stated that a patch is in preparation and that rollback scenarios are being evaluated. However, the project has not officially confirmed the exploit's cause, the exact quantity of tokens minted, or the volume transferred to exchanges.

By the time of publication, Harmony had not responded to a request for comment from Cointelegraph.

Harmony's public statement came as a reaction to claims made by an X account known as “Juiceberg.” This account alleged that the unauthorized ONE tokens were generated through empty blocks. It further asserted that around 2.8 billion of these tokens were rapidly moved to various exchanges amid a decline in ONE's market price.

According to Juiceberg's estimation, the attacker still holds approximately 115 million ONE on-chain, a figure that constitutes 2.9% of the total tokens allegedly created. The rest of the funds have reportedly been either sold off or are currently sitting in exchange deposit wallets. These specific claims could not be independently verified by Cointelegraph.

The market reacted sharply to the news. Data from CoinGecko at the time of writing indicated that the price of ONE had plummeted by 33.9% within the preceding 24-hour period.

This latest event is not the first major security issue for the network; it comes after the June 2022 hack of Harmony's Horizon Bridge. That earlier breach resulted in the theft of cryptocurrencies valued at approximately $100 million. Subsequently, the FBI attributed responsibility for that attack to the Lazarus Group, a cybercrime organization linked to North Korea.