Ontology pauses mainnet block production due to potential security issue

Ontology, a blockchain network, stopped producing new blocks on its mainnet on August 31 after developers found a potential security issue during a routine check. The pause has frozen all onchain transactions while the network’s technical team and validators review the situation.

The last block, number 20,770,893, was created at 4:24 a.m. ET (8:24 UTC), according to the network’s official block explorer. Ontology stated that no confirmed security incident or asset loss has been detected so far.

Network and bridge transactions halted

With block production paused, no new transactions can be processed on Ontology. The network’s bridge interface remains accessible, but transfers requiring an Ontology-side transaction cannot complete until block production resumes.

Exchange Upbit has suspended deposits and withdrawals for ONT, ONG, and MBL tokens on the Ontology network. Trading for these assets continues, and the exchange will reopen transfers only after confirming safety.

No restart timeline announced

Ontology has not set a timeline for resuming block production. The network will remain paused until the review is complete and any necessary upgrades are applied. Users do not need to move their assets during the pause, according to the project.

The team described the suspension as a preventive measure, not a response to an active attack or confirmed loss of funds.

What is confirmed

• Ontology halted mainnet block production on August 31 at 4:24 a.m. ET.
• No confirmed security incident or asset loss has been reported.
• Onchain transactions and Ontology-side bridge transfers are frozen.
• Upbit suspended deposits and withdrawals for ONT, ONG, and MBL on Ontology.
• The pause is preventive, with no restart date announced.

Sources

• The Defiant