Moonwell Probes $8.7 Million Exploit on Base

Moonwell is a decentralized lending protocol operating on Base, allowing users to borrow crypto assets against deposited collateral. The incident centered on its MAMO Core Market and underscores a recurring vulnerability in DeFi lending: thinly traded collateral can be manipulated to appear more valuable than it is, enabling attackers to take out loans that are not adequately backed. The episode highlights the importance of reliable pricing mechanisms and conservative risk limits.

On Aug. 27, 2026, blockchain security firms CertiK and PeckShield estimated losses at about $8.7 million. The attacker allegedly manipulated the collateral price of the relatively illiquid MAMO token, then borrowed cbBTC from the mCBTC market and consolidated the proceeds in DAI. Moonwell said it was investigating and set borrowing caps across all Core Markets on Base to 1 wei. It also reduced supply caps for MAMO and WELL to 1 wei to prevent new exposure while containing the incident.