Analysis of the Notional Finance Security Breach

On September 4, 2026, decentralized lending platform Notional Finance suffered a hack resulting in approximately $1.73 million in losses. The SlowMist Security Team identified the root cause as a vulnerability in the ExchangeRate._convertToETH function within the Escrow contract, where a signed integer's absolute value was improperly converted to uint128, leading to a failure in collateral checks.