CVE-2021-38194: Arcworks Ark-r1cs-Std

Critical severity, CVSS 9.8. EPSS: 1.3% chance of exploitation in the next 30 days.

An issue was discovered in the ark-r1cs-std crate before 0.3.1 for Rust. It does not enforce any constraints in the FieldVar::mul_by_inverse method. Thus, a prover can produce a proof that is unsound but is nonetheless verified.

Affected products

• Arcworks Ark-r1cs-Std: before 0.3.1 (fixed in 0.3.1)

Published 2021-08-08. Last modified 2026-06-17.