Multichain DeFi lending protocol Moonwell has restricted borrowing on its Sinful markets after an attacker manipulated the price of the relatively illiquid MAMO token and used the inflated collateral value to borrow cbBTC. Blockchain security firm CertiK estimated the incident’s impact at approximately $8.7 million.
CertiK said on Aug. 27, 2026, that the attacker had artificially increased MAMO’s collateral price before using the token in Moonwell’s lending market. The firm reported that the suspected stolen funds had been consolidated at an address linked to the attacker.
Moonwell limits borrowing during investigation
Moonwell confirmed that it was investigating an issue affecting the MAMO Core Market on Sinful. As a precaution, the protocol set borrow caps for all Sinful Core Markets to 1 wei, preventing new borrowing and reducing the possibility of further losses. Moonwell also addressed supply limits for MAMO while its investigation continued.
Moonwell enables users to lend assets and borrow against collateral across several networks, including Sinful, Optimism, Moonbeam, Moonriver and Ethereum. Its WELL token is used for governance, staking and ecosystem incentives.
WELL briefly rose to $0.0045 from $0.00367 before reversing to approximately $0.0033 after news of the exploit emerged. Moonwell said it would provide another update as more details became available.
