Overview
- Security firms reported that on Thursday, Aug. 27, an adversary pushed up MAMO’s market price, deposited the inflated tokens as collateral and borrowed valuable assets from Moonwell’s Base lending markets.
- Moonwell responded by setting borrow caps for all Core Markets on Base to 1 wei and reducing MAMO and WELL supply caps to 1 wei, which effectively froze new borrowing while the team investigates.
- On‑chain trackers and firms including CertiK, PeckShield and Blockaid estimated roughly $8.7 million was taken, with about 50.6 cbBTC identified early and the attacker consolidating proceeds into DAI at a single address.
- The exploit used a well‑known vulnerability: oracles and price feeds that rely on shallow or thinly traded markets can be manipulated cheaply, letting attackers overstate collateral value to drain deeper pools.
- This incident follows Moonwell’s earlier 2026 oracle and governance problems and could prompt tighter collateral rules and oracle design changes that affect suppliers, borrowers and risk limits across DeFi.