Aave Faces $6 Billion Deposit Exodus After Kelp Hack Exposes DeFi Lender's Structural Vulnerability

Aave has witnessed a massive exodus of $6.6 billion in deposits, not due to a direct hack, but as a result of a broader DeFi vulnerability. The protocol's total value locked plummeted from $26.4 billion on April 18 to approximately $20 billion by Sunday morning, according to DefiLlama. The AAVE token suffered a 16% decline to $92, while daily fees surged to $1.99 million amidst a wave of liquidations over the weekend. Depositors are fleeing Aave due to the protocol's unintended exposure to a hole created by an external hack. Attackers drained 116,500 rsETH from Kelp's bridge on Saturday and used the stolen tokens as collateral on Aave V3 to borrow wrapped ether. On-chain trackers estimate the Aave-specific borrow to be around $196 million, with total positions across Aave, Compound, and Euler totaling $236 million. As the largest lending protocol in DeFi, Aave enables users to deposit crypto to earn yield, while others borrow against collateral. Kelp, a liquid restaking protocol, takes already-staked ether on Ethereum and channels it through a separate yield-generating system called EigenLayer, issuing a receipt token, rsETH, in exchange. This rsETH is what users trade and, crucially, what some users posted as collateral on Aave to borrow against. On Saturday, attackers tricked Kelp's cross-chain bridge into releasing 116,500 rsETH, valued at approximately $292 million, to a controlled address. They then deposited the stolen rsETH onto Aave V3 as collateral and borrowed wrapped ether against it. Aave initially stated that the Umbrella reserve would cover any deficit but later softened its stance to exploring paths to offset the deficit. The concentration of Aave's loan book on Ethereum, with $14.24 billion of the $17.82 billion in outstanding borrows, explains why the damage is significant. WETH accounts for 39.49% of all loans on the protocol, making the attacked collateral-to-WETH pair a dominant part of Aave's book. Stani Kulechov, Aave's founder, emphasized that the exploit was external and the protocol's contracts were not compromised. However, Aave accepted a liquid restaking token as collateral, and the token's backing vanished on a bridge Aave does not control, leaving depositors vulnerable to losses. The whitelisting of liquid restaking tokens across major lending protocols was based on their yield and representation of Ethereum's locked value. Risk models priced them under the assumption they would hold peg under normal conditions, but none accounted for a scenario where the collateral becomes worthless due to a bridge exploit on an unrelated chain. The token price now reflects concerns about whether the Umbrella reserve is sufficient to cover the resulting hole and whether stkAAVE holders backing that reserve will absorb the loss.