Developers behind the Harmony blockchain protocol have officially acknowledged a significant security breach that allowed the unauthorized generation of a large volume of additional ONE tokens, the network’s native digital asset.
The confirmation comes after on-chain observers first highlighted unusual activity involving the sudden appearance of roughly four billion new tokens.
According to reports circulating on social media platforms earlier, an unidentified party succeeded in minting approximately four billion ONE tokens without proper authorization.
We are working with our team and appropriate exchanges to stop and freeze the funds.
We are working on a patch and rollback options.
Will update when we have new information. https://t.co/XB0nCwTAyN
— Harmony 💙 (@harmonyprotocol) August 12, 2026
This quantity represents a substantial expansion of the existing circulating supply—estimated previously at around 15 billion tokens—amounting to an increase of roughly one-quarter.
Industry professionals have now generally noted that the process appeared to leverage empty blocks in a manner that bypassed standard verification checks, and that the network’s total supply reporting mechanism did not immediately register the expansion.
Following the minting, a large portion of the newly created tokens—reported at around 2.8 billion—was rapidly moved toward cryptocurrency exchanges.
This transfer coincided with a sharp decline in the price of ONE, which dropped by approximately 26 to 34 percent within a short period, trading near $0.0008 at one point.
Analysts indicated that the remaining balance held by the responsible party on the chain itself stood at roughly 115 million ONE, or about 2.9 percent of the total minted amount, while the vast majority had already reached exchange deposit addresses or been sold.
In a public statement, the Harmony team confirmed the incident and outlined its immediate response.
Officials stated they are collaborating with their internal staff and relevant trading platforms to halt further movement of the affected funds and to freeze associated assets.
The team is actively developing a software patch intended to block any additional unauthorized minting and is simultaneously evaluating the possibility of a network rollback.
Such a measure would involve reverting the blockchain to a state prior to the exploit, potentially neutralizing the impact of the illicitly created tokens that remain on the network.
Harmony has also paused its cross-chain bridge service as a precautionary step and issued an urgent call for validators to upgrade to a newly released software version designed to prevent further minting.
The project indicated that additional updates would follow once more details become available, noting that a full technical investigation into the root cause remains ongoing.
This event marks another security challenge for the layer-1 network, which previously experienced a major incident in 2022 when its Horizon bridge suffered a substantial loss of assets valued near $100 million.
A separate issue in late 2023 involving staking logic also led to the unintended creation of tens of millions of extra ONE tokens before an emergency fix was applied.
Market reaction has been swift, with the token’s value reflecting the sudden increase in supply and the uncertainty surrounding recovery efforts.
The Harmony team continues to monitor the situation and has requested exchanges to take action against specific wallet addresses linked to the activity. As the investigation proceeds, the focus remains on containing the impact, restoring confidence among users and validators, and implementing lasting safeguards against similar vulnerabilities.