CVE-2026-34067: Nimiq Proof-Of-Stake

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

nimiq-transaction provides the transaction primitive to be used in Nimiq's Rust implementation. Prior to version 1.3.0, `HistoryTreeProof::verify` panics on a malformed proof where `history.len() != positions.len()` due to `assert_eq!(history.len(), positions.len())`. The proof object is derived from untrusted p2p responses (`ResponseTransactionsProof.proof`) and is therefore attacker-controlled at the network boundary until validated. A malicious peer could trigger a crash by returning a crafted inclusion proof with a length mismatch. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.

Affected products

• Nimiq Nimiq Proof-Of-Stake: before 1.3.0 (fixed in 1.3.0)

Published 2026-04-22. Last modified 2026-06-17.