How One Missing Assert Drained $1.14M From Aftermath Finance — A Signed Integer Exploit on Sui

Two security breaches on the Sui network caused significant losses. On April 29, 2026, Aftermath Finance lost $1.14M USDC due to a signed integer exploit where a negative fee bypassed validation. Similarly, on October 15, 2025, Typus Finance lost $3.44M in SUI, xBTC, and suiETH. This occurred because a Move code line silently discarded an authorization check result. Both incidents highlight how missing assert statements or ignored function results can lead to drained liquidity pools.