According to CoinMeta, on September 4th, Ethereum was attacked, and approximately $1.7 million was stolen from managed contracts. The attackers exploited the trading pair path in fcash within Notional V2 to control multiple wallets and carry out extreme cross-maturity long-short operations. Freecollateral only checks solvency at the account level and failed to prevent the attackers from isolating risks between accounts and maturities, resulting in significant short-term credit risks and future vulnerabilities.