Moonwell's $1.12 nightmare: A pricing glitch just let bots seize millions in ETH collateral
A Chainlink oracle glitch briefly valued cbETH at $1.12, causing bots to seize $2.44 million in collateral and incur $1.8 million in bad debt for Moonwell.Summary
DeFi lender Moonwell suffered nearly $1.8 million in bad debt after a pricing error caused the value of Coinbase Wrapped ETH (cbETH) to plummet to approximately $1.12 instead of its actual price of around $2,200. This occurred because a system update configured a Chainlink price oracle to value cbETH based only on its ratio to ETH (about 1.12), ignoring the real USD price. Liquidation bots exploited this, repaying minimal debt to seize over 1,096 cbETH, wiping out borrower collateral. The incident also allowed some users to borrow cbETH cheaply. While Moonwell quickly limited activity, fixing the oracle required a governance vote with a five-day timelock. Security auditor Krum Pashov noted that GitHub commits related to the faulty proposal were co-authored by the AI coding assistant Claude Opus 4.6, sparking debate over AI-assisted coding risks in DeFi.
(Source：CoinDesk)