What happened
An interest-rate model update permanently locked assets in Percent Finance's USDC, WBTC and ETH markets. The replacement models returned values in a format incompatible with those markets, causing routine operations and further model updates to fail.
Technical root cause
An incompatible return-value interface broke interest-rate calls. Because those calls also guarded model replacement, the update disabled both normal market operations and the available repair path.
How it happened
- The multisignature team replaced the interest-rate models, assuming every market used the same interface.
- Three older markets expected an error code and a rate, but the replacement model returned only one value.
- Rate calls failed before deposits, borrowing, repayments and withdrawals could complete.
- Updating the rate model required the same failing calls, preventing a repair through that route. The team later deployed replacement markets, but the locked assets remained inaccessible.
Protocol details
Classification
Borrowing and Lending
Protocol Type
Lending
Affected asset / contract
PCT
Protocol links
Website
@PercentFinance
Evidence
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