# CVE-2026-34067: nimiq-transaction: Panic via `HistoryTreeProof` length mismatch

Source: https://junglewise.ai/threats/cve-2026-34067-nimiq-transaction-panic-via-historytreeproof-length-mismatch  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-22. Updated: 2026-05-11  
License: CC BY 4.0 with a link back

CVE-2026-34067 · Severity: low · CVSS 3.1 · Published 2026-04-22

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.

Technologies: [Nimiq Proof-Of-Stake](https://junglewise.ai/threats/technologies/nimiq-proof-of-stake). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io), [Nimiq](https://junglewise.ai/threats/vendors/nimiq).

## Quick answers

**Is CVE-2026-34067 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34067 being exploited in the wild.

**How severe is CVE-2026-34067?** Low severity, with a CVSS score of 3.1, published 22 April 2026.

**Which products and versions are affected?** nimiq-transaction (crates.io) <= 0.2.0, SEMVER:introduced=0,last_affected=0.2.0.

**Is there a fix for CVE-2026-34067?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-34067?** Check whether you run nimiq-transaction (crates.io) or Nimiq Proof-Of-Stake at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- nimiq-transaction (crates.io) <= 0.2.0, SEMVER:introduced=0,last_affected=0.2.0
- Nimiq Proof-Of-Stake

## Identifiers

- CVE-2026-34067
- GHSA-264v-m8fm-76jm

## References

- [https://api.github.com/users/1seal](https://api.github.com/users/1seal)
- [https://github.com/1seal](https://github.com/1seal)
- [https://api.github.com/users/1seal/gists%7B/gist_id%7D](https://api.github.com/users/1seal/gists%7B/gist_id%7D)
- [https://api.github.com/users/1seal/repos](https://api.github.com/users/1seal/repos)
- [https://avatars.githubusercontent.com/u/239602944?v=4](https://avatars.githubusercontent.com/u/239602944?v=4)
- [https://api.github.com/users/1seal/events%7B/privacy%7D](https://api.github.com/users/1seal/events%7B/privacy%7D)

## Related threats

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- [nimiq-blockchain: Peer-triggerable panic during history sync](https://junglewise.ai/threats/cve-2026-34066-nimiq-blockchain-peer-triggerable-panic-during-history-sync)
- [nimiq-primitives: Node crash due to missing interlink validation in election macro block proposals](https://junglewise.ai/threats/cve-2026-34065-nimiq-primitives-node-crash-due-to-missing-interlink-validation)
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- [Nimiq's network-libp2p is a Nimiq network implementation based on libp2p. Prior to version 1.3.0, `network-libp2p`…](https://junglewise.ai/threats/cve-2026-34063-nimiq-s-network-libp2p-is-a-nimiq-network-implementation-based-on)