CVE-2025-52884

RISC Zero is a zero-knowledge verifiable general computing platform, with Ethereum integration. The risc0-ethereum repository contains Solidity verifier contracts, Steel EVM view call library, and supporting code. Prior to versions 2.1.1 and 2.2.0, the Steel.validateCommitment Solidity library function will return true for a crafted commitment with a digest value of zero. This violates the semantics of validateCommitment, as this does not commitment to a block that is in the current chain. Because the digest is zero, it does not correspond to any block and there exist no known openings. As a result, this commitment will never be produced by a correct zkVM guest using Steel and leveraging this bug to compromise the soundness of a program using Steel would require a separate bug or misuse of the Steel library, which is expected to be used to validate the root of state opening proofs. A fix has been released as part of risc0-ethereum 2.1.1 and 2.2.0. Users for the Steel Solidity