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::isblockproven causes the function to return true without performing any cryptographic verification when getinterlinkhops 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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46539.json",
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-345"
]
}