Harmony's Unauthorized Minting Incident Floods Exchanges with Billions in ONE

Harmony's native token ONE has been impacted by an unauthorized minting incident that has flooded exchanges with billions of tokens. The blockchain network released an emergency validator patch on August 12 to prevent further minting, but the impact of the attack is still being assessed.

According to onchain researcher Juiceberg, approximately 4 billion ONE (about 26% of the supply) were illicitly minted, with around 2.8 billion reaching exchanges. Harmony has not independently confirmed these figures, leaving the number and ultimate treatment of the affected tokens unresolved.

The patch addresses two weaknesses in cross-shard receipts, which carry transaction results between parts of the network. The first flaw allowed an empty signer record to pass a quorum check, while the second affected how the network recorded that a receipt had already been spent. Harmony has paused its bridge during the response and published four implicated wallet addresses.

The project is weighing a full blockchain rollback to remove the excess supply, but no decision has been made. This would be a significant undertaking, with potential risks for DeFi, CEX listings, and token holders.