CVE-2026-46654

Plonky3 MultiField32Challenger: transcript malleability and challenge entropy loss

State: Published
Severity: 8.9 High
Published: Jun 10, 2026
Updated: Jun 11, 2026
Reserved: May 15, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.9 High	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	GitHub_M

Weaknesses

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

Affected Products

Product	Versions
Plonky3Plonky3	< 0.4.3Affected >= 0.5.0, < 0.5.3Affected

References

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

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