What happened
On April 26, 2025, a flash-loan attacker exploited an Impermax V3 collateral-valuation discrepancy on Base, stealing around $300,000 and leaving additional liquidity at risk. The attacker inflated uncollected Uniswap V3 fees, borrowed against the overstated collateral, then auto-compounded at a wrong tick to make the position underwater and dilute lenders through bad-debt restructuring.
How it happened
- The attacker used a flash loan to create a low-liquidity Uniswap V3 collateral position and push its tick to an extreme price.
- Repeated swaps accumulated large uncollected fees, overstating the collateral's value.
- The attacker borrowed from Impermax against that fee-inflated position.
- They reinvested the fees at the wrong tick, leaving the position underwater when the tick returned.
- Calling
restructureBadDebtclosed the position and diluted lenders, allowing value extraction from the available liquidity.
Protocol details
Classification
Protocol Logic / Yield Aggregator / Token & Share Accounting
Protocol Type
Lending
Implementation language
Solidity
Protocol links
Website
@impermaxfinance
Security review history
- Guardian Audits View report
- BailSec View report
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