CVE-2026-46654: PLONKY3

High severity, CVSS 8.9. EPSS: 0.1% chance of exploitation in the next 30 days.

Plonky3 is a toolkit for polynomial IOPs (PIOPs). Prior to versions 0.4.3 and 0.5.3, an attacker controlling prover-side observations can craft distinct transcripts that produce identical challenges, breaking the binding property of Fiat-Shamir. This issue has been patched in versions 0.4.3 and 0.5.3.

Affected products

• PLONKY3 PLONKY3: before 0.4.3 (fixed in 0.4.3); from 0.5.0, before 0.5.3 (fixed in 0.5.3)

Published 2026-06-10. Last modified 2026-07-23.