CVE-2026-40323: Succinct SP1

High severity, CVSS 7.5. EPSS: 0.2% chance of exploitation in the next 30 days.

SP1 is a zero‑knowledge virtual machine that proves the correct execution of programs compiled for the RISC-V architecture. In versions 6.0.0 through 6.0.2, a soundness vulnerability in the SP1 V6 recursive shard verifier allows a malicious prover to construct a recursive proof from a shard proof that the native verifier would reject. Version 6.1.0 fixes the issue.

Affected products

• Succinct SP1: from 6.0.0, before 6.1.0 (fixed in 6.1.0)

Published 2026-04-18. Last modified 2026-06-17.