Harmony Activates Mint Bug Fix and Moves Toward Rollback After ONE Exploit

Highlights:

• Harmony activated an emergency mint bug fix and is considering a rollback after unauthorized ONE token creation.
• The team traced 10,288 transfers across 409 wallets and worked with exchanges to block suspicious deposits.
• The exploit minted around 4 billion ONE, triggering heavy selling and pushing the token to record lows.

Harmony has activated a fix for the minting bug behind the recent ONE token incident and is now working on a possible blockchain rollback. The layer-1 blockchain said on August 13 that it is coordinating with validators and cryptocurrency exchanges to agree on the next steps. Harmony also plans to release a full list of wallets linked to the exploiter.

The update follows an emergency response that began after unauthorized ONE tokens appeared on the network. Harmony said it traced 10,288 transfers across 409 wallets that received fraudulently minted tokens. The team also alerted exchange partners about hundreds of suspicious deposits. According to Harmony, exchanges then blocked wallets connected to the activity.

We’re working on a rollback approach, with alignment from validators and exchanges on the specific path forward.

The mint bug fix has been activated, and a full list of exploiter wallets will be released soon. https://t.co/aIwkRf4CY3

— Harmony 💙 (@harmonyprotocol) August 13, 2026

Harmony Emergency Patch Stops Further ONE Minting

Harmony released an emergency patch and asked all validators to upgrade their nodes. The project said the patch prevents any additional unauthorized minting. However, it did not immediately solve the issue of tokens that had already been created and moved across the network.

The GitHub release for Harmony Mainnet v2026.1.1 was published on August 12. Harmony also paused its bridge following the incident while developers worked on securing the network and limiting further damage. Validator adoption of the emergency update moved quickly. Harmony said 53% of its validators had completed the upgrade only four hours after the patch was released. Meanwhile, the team continued tracing the movement of the affected tokens and working with exchanges.

Harmony said a rollback currently appears to be the preferred practical option. The project is discussing the exact approach with validators and exchanges before taking further action. 

A blockchain rollback generally involves returning the network to an earlier state to reverse transactions or changes linked to an incident. However, Harmony has not yet published the exact rollback point, implementation process, or final plan. Therefore, the treatment of the already minted ONE tokens remains under discussion.

ONE Exploit Triggered Heavy Selling Pressure

The incident emerged after on-chain researcher Juiceberg reported that around 4 billion ONE tokens, equal to roughly 26% of the existing supply, had been created without authorization. The researcher also said about 2.8 billion ONE were moved toward exchanges.

The sudden increase in supply was followed by heavy selling. Crypto2Community reported on August 12 that ONE fell to a new all-time low of $0.0005357, after trading as high as $0.00124 during the previous 24-hour period. The token later recovered part of the decline.

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

Harmony has not yet released a complete technical report explaining the incident. For now, the project is focused on securing the network, tracing affected wallets, coordinating with exchanges, and deciding how to handle the fraudulently minted tokens.