Plonky3 MultiField32Challenger: transcript malleability and challenge entropy loss
CVE-2026-46654

8.9HIGH

Key Information:

Vendor

Plonky3

Status
Plonky3
Vendor
CVE Published:
10 June 2026

What is CVE-2026-46654?

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 Version(s)

Plonky3 < 0.4.3 < 0.4.3

Plonky3 >= 0.5.0, < 0.5.3 < 0.5.0, 0.5.3

References

https://github.com/Plonky3/Plonky3/security/advisories/GH...
x_refsource_CONFIRM

CVSS V4

Score:
8.9
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.