A logic error in the Nimiq block proof verification process allows attackers to bypass quorum requirements using manipulated BLS signatures.
Description
A logic error in the Nimiq block proof verification process allows attackers to bypass quorum requirements using manipulated BLS signatures.
AI Analyst Comment
Remediation
Update Unknown Multiple Products to the latest version. Monitor for exploitation attempts and review access logs.
---METADATA---
VENDOR: Nimiq
PRODUCT: nimiq-block
AFFECTED_VERSIONS: Prior to 1.3.0
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Description Summary:
A logic error in the Nimiq block proof verification process allows attackers to bypass quorum requirements using manipulated BLS signatures.
Executive Summary:
A critical verification flaw in the Nimiq block implementation allows malicious actors to bypass security protocols through signature index collisions.
Vulnerability Details
CVE-ID: CVE-2026-33471
Affected Software: Nimiq Block
Affected Versions: Prior to 1.3.0
Vulnerability: The vulnerability exists in
SkipBlockProof::verify, where improper index casting allows multiple out-of-range indices to collide into the same in-range slot, enabling signature multiplication.Business Impact
This flaw undermines the consensus mechanism of the Nimiq implementation. An attacker could potentially validate fraudulent blocks, leading to double-spending or network instability. The CVSS score of 9.6 highlights the extreme risk to the integrity of the blockchain-based system.
Remediation Plan
Immediate Action: Update to Nimiq block version 1.3.0 or later immediately.
Proactive Monitoring: Monitor consensus logs for any anomalous block verification failures or irregularities in validator signature aggregation.
Compensating Controls: No effective workarounds exist; immediate application of the vendor-provided patch is required to maintain network security.
Exploitation Status
Public Exploit Available: false
Analyst Notes: As of Apr 22, 2026, there is no public information indicating active exploitation of this vulnerability. However, due to the nature of the flaw, the potential for exploitation is high.
Analyst Recommendation
All operators running Nimiq infrastructure must update to version 1.3.0 without delay. The integrity of the consensus mechanism is at stake, and no alternative mitigations can compensate for the underlying logic vulnerability.