Core DAO announced an emergency hard fork after validators were reported to have received more CORE rewards than the protocol intended.

Validators normally issue CORE according to the blockchain’s reward schedule, and excess rewards would indicate a deviation from the expected issuance.

Core said the incident had been contained and that malicious validators could no longer draw excess rewards. The upcoming fork will be a forward upgrade that does not roll back the network or reverse any confirmed transactions. An earlier status update on Monday indicated that a small number of validators had accrued rewards above the intended issuance. Core added that user assets remained safe and that a technical postmortem would be published.

Several exchanges restricted CORE transfers during the incident. Coinbase paused sends and receives on the Core network, while Bithumb and Coinone suspended deposits and withdrawals citing suspected or confirmed security concerns. Bitget paused CORE deposits and withdrawals, describing the action as wallet maintenance, and LBank suspended deposits, saying the suspension was required by the project.

Core has not disclosed the amount of excess CORE issued, the duration of the activity, or whether the additional tokens entered circulation, and it has not explained the vulnerability that allowed the over-issuance. Core said it would publish a technical postmortem and had not responded to a request for comment.