CVE-2025-66016Network attack vector

Private-key extraction via incomplete ZK-proof verification

Published Nov 25, 2025 · Updated Nov 25, 2025

Cryptographic verification failure in Lockness cggmp21 before 0.6.3 allows attackers controlling one signer to reconstruct the private key. The Paillier-Blum modulus ZK-proof verifier used during auxiliary key generation accepts a proof without performing a required integrity check. Control of one protocol signer is sufficient, breaking the threshold guarantee and exposing the complete ECDSA signing key.

CVSS severity9.3
Critical
EPSS probability0.19%
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 Lockness cggmp21 before 0.6.3 allows attackers controlling one signer to reconstruct the private key. The Paillier-Blum modulus ZK-proof verifier used during auxiliary key generation accepts a proof without performing a required integrity check. Control of one protocol signer is sufficient, breaking the threshold guarantee and exposing the complete ECDSA signing key.

The record

CVE
CVE-2025-66016
Published
Nov 25, 2025
Updated
Nov 25, 2025
Vendor
Lockness
Product
cggmp21
Classifications
CWE-347, CWE-345, T1552.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 25, 2025Record 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=< 0.6.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Lockness · cggmp21version=< 0.6.3

Published CVSS scores

9.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature
CWE-345Insufficient Verification of Data Authenticity
T1552.004Unsecured Credentials: Private Keys

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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