CVE-2026-46539: CWE-345: Insufficient Verification of Data Authenticity in nimiq core-rs-albatross
Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.4.0, a logic flaw in BlockInclusionProof::is_block_proven causes the function to return true without performing any cryptographic verification when get_interlink_hops yields an empty hop list. This occurs when the target block is at the election block position immediately preceding the election head's epoch. An attacker providing transaction inclusion proofs can forge a MacroBlock header for that epoch position and have it accepted as "proven" without any hash or signature verification. This issue has been patched in version 1.4.0.
AI Analysis
Technical Summary
Nimiq's Rust implementation of the Albatross consensus protocol contains a vulnerability (CVE-2026-46539) in the BlockInclusionProof::is_block_proven function. Before version 1.4.0, when get_interlink_hops returns an empty list for a block at the election block position immediately before the election head's epoch, the function returns true without performing cryptographic verification. This allows an attacker to forge a MacroBlock header for that epoch position and have it accepted as proven without verifying its hash or signature. This flaw compromises the integrity verification of blocks in the protocol. The vulnerability has been addressed in version 1.4.0.
Potential Impact
The vulnerability allows an attacker to forge a MacroBlock header at a specific election block position and have it accepted as valid without cryptographic verification. This compromises the integrity of the blockchain consensus by enabling acceptance of unauthenticated blocks. There is no direct confidentiality or availability impact reported. The CVSS score is 5.9 (medium severity), reflecting the integrity impact with network attack vector and high attack complexity.
Mitigation Recommendations
Upgrade to Nimiq core-rs-albatross version 1.4.0 or later, where this vulnerability is patched. No other mitigation is indicated or required.
CVE-2026-46539: CWE-345: Insufficient Verification of Data Authenticity in nimiq core-rs-albatross
Description
Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.4.0, a logic flaw in BlockInclusionProof::is_block_proven causes the function to return true without performing any cryptographic verification when get_interlink_hops yields an empty hop list. This occurs when the target block is at the election block position immediately preceding the election head's epoch. An attacker providing transaction inclusion proofs can forge a MacroBlock header for that epoch position and have it accepted as "proven" without any hash or signature verification. This issue has been patched in version 1.4.0.
CVSS v3.1
Score 5.9medium
Affected software
pkg:cargo/github/nimiq/core-rs-albatrossRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Nimiq's Rust implementation of the Albatross consensus protocol contains a vulnerability (CVE-2026-46539) in the BlockInclusionProof::is_block_proven function. Before version 1.4.0, when get_interlink_hops returns an empty list for a block at the election block position immediately before the election head's epoch, the function returns true without performing cryptographic verification. This allows an attacker to forge a MacroBlock header for that epoch position and have it accepted as proven without verifying its hash or signature. This flaw compromises the integrity verification of blocks in the protocol. The vulnerability has been addressed in version 1.4.0.
Potential Impact
The vulnerability allows an attacker to forge a MacroBlock header at a specific election block position and have it accepted as valid without cryptographic verification. This compromises the integrity of the blockchain consensus by enabling acceptance of unauthenticated blocks. There is no direct confidentiality or availability impact reported. The CVSS score is 5.9 (medium severity), reflecting the integrity impact with network attack vector and high attack complexity.
Mitigation Recommendations
Upgrade to Nimiq core-rs-albatross version 1.4.0 or later, where this vulnerability is patched. No other mitigation is indicated or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-14T20:42:31.368Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a28a8098dd33fbd8595f122
Added to database: 06/09/2026, 23:55:53 UTC
Last enriched: 06/17/2026, 08:55:56 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 78
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