CVE-2026-46654Network attack vector

Proof forgery via non-injective transcript encoding

Published Jun 10, 2026 · Updated Jun 10, 2026

Cryptographic verification failure in Plonky3 before 0.4.3 and 0.5.0 through 0.5.2 allows remote attackers to forge Fiat-Shamir proofs. MultiField32Challenger::duplexing uses untagged partial chunks, lossy modular limb conversion, and floor-divided limb counts, so distinct prover observations collapse to identical challenges. Exploitation requires control of prover-side observations and compromises proof integrity without reported data disclosure or service interruption.

CVSS severity8.9
High
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cryptographic verification failure in Plonky3 before 0.4.3 and 0.5.0 through 0.5.2 allows remote attackers to forge Fiat-Shamir proofs. MultiField32Challenger::duplexing uses untagged partial chunks, lossy modular limb conversion, and floor-divided limb counts, so distinct prover observations collapse to identical challenges. Exploitation requires control of prover-side observations and compromises proof integrity without reported data disclosure or service interruption.

The record

CVE
CVE-2026-46654
Published
Jun 10, 2026
Updated
Jun 10, 2026
Vendor
Plonky3
Product
Plonky3
Classifications
CWE-1240, CWE-345, T1565
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.4.3
  2. Affected versionversion=>= 0.5.0, < 0.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Plonky3 · Plonky3version=< 0.4.3; version=>= 0.5.0, < 0.5.3

Published CVSS scores

8.9GitHubCVSS: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 describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1240Use of a Cryptographic Primitive with a Risky Implementation
CWE-345Insufficient Verification of Data Authenticity
T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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