soroban-sdk is a Rust SDK for Soroban contracts. Prior to 22.0.11, 23.5.3, and 25.3.0, The Fr (scalar field) types for BN254 and BLS12-381 in soroban-sdk compared values using their raw U256 representation without first reducing modulo the field modulus r. This caused mathematically equal field elements to compare as not-equal when one or both values were unreduced (i.e., >= r). The vulnerability requires an attacker to supply crafted Fr values through contract inputs, and compare them directly without going through host-side arithmetic operations. Smart contracts that rely on Fr equality checks for security-critical logic could produce incorrect results. The impact depends on how the affect





