A draft amendment filed on the XRPL standards repository this week contains a single line that carries outsized weight for DeFi security: "Flash loan attacks are structurally impossible. XRPL transactions are atomic without composable intra-transaction calls." The note appeared in the Security Considerations section of a proposal to add concentrated liquidity and StableSwap-style pools to the chain's native AMM.
The architectural reason is precise. Flash loan attacks require at least three nested operations inside one transaction — borrow, manipulate, repay — all before settlement. XRPL transactions are atomic like Ethereum's, but unlike Ethereum they cannot call into another contract mid-execution. That single constraint closes the entire exploit class.
CoinDesk