CVE-2026-46654 PUBLISHED

Plonky3 MultiField32Challenger: transcript malleability and challenge entropy loss

Assigner: GitHub_M
Reserved: 15.05.2026 Published: 10.06.2026 Updated: 11.06.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
CVSS Score: 8.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	High
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Plonky3
Product	Plonky3
Versions	Version < 0.4.3 is affected Version >= 0.5.0, < 0.5.3 is affected

References

https://github.com/Plonky3/Plonky3/security/advisories/GHSA-vj64-rjf3-w3v7

Problem Types

CWE-1240: Use of a Cryptographic Primitive with a Risky Implementation CWE
CWE-345: Insufficient Verification of Data Authenticity CWE