# CVE-2026-34069: nimiq-consensus panics via RequestMacroChain micro-block locator


- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 13 Apr 2026
- **Updated:** 14 Apr 2026
- **Also known as:** GHSA-48m6-486p-9j8p

## What is CVE-2026-34069?

CVE-2026-34069 is a medium-severity vulnerability in nimiq core-rs-albatross, published on 13 Apr 2026. 

### Official description

nimiq/core-rs-albatross is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. In versions 1.2.2 and below, an unauthenticated p2p peer can cause the RequestMacroChain message handler task to panic. Sending a RequestMacroChain message where the first locator hash on the victim’s main chain is a micro block hash (not a macro block hash) causes said panic. The RequestMacroChain::handle handler selects the locator based only on "is on main chain", then calls get_macro_blocks() and panics via .unwrap() when the selected hash is not a macro block (BlockchainError::BlockIsNotMacro). This issue has been fixed in version 1.3.0.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-34069?

2 open source packages ship an affected version, including nimiq-consensus. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nimiq-consensus` | crates.io | All versions to 1.2.2 | None |
| `nimiq-consensus` | crates.io | All versions to 1.2.2 | None |

Products: Nimiq Nimiq Proof-of-Stake.

## How do I fix CVE-2026-34069?

No fix has been published for CVE-2026-34069 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34069 being exploited?

There is no known exploitation of CVE-2026-34069 in the wild and no public exploit code.

## Other vulnerabilities in nimiq core-rs-albatross

- [CVE-2026-33471](https://insights.sbomify.com/CVE-2026-33471/): nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation (critical 9.6)
- [CVE-2026-40093](https://insights.sbomify.com/CVE-2026-40093/): nimiq-blockchain is missing a wall-clock upper bound on block timestamps (high 8.1)
- [CVE-2026-34063](https://insights.sbomify.com/CVE-2026-34063/): network-libp2p: Peer can crash the node by opening discovery protocol substream twice (high 7.5)
- [CVE-2026-34065](https://insights.sbomify.com/CVE-2026-34065/): nimiq-primitives: Node crash due to missing interlink validation in election macro block proposals (high 7.5)
- [CVE-2026-32605](https://insights.sbomify.com/CVE-2026-32605/): Nimiq: Remote crash via off-by-one signer bounds check in proposal buffer (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34069 and fix it if it is affected.

What it is: CVE-2026-34069 is a medium-severity vulnerability in nimiq core-rs-albatross, published on 13 Apr 2026. 
Exploitation: There is no known exploitation of CVE-2026-34069 in the wild and no public exploit code.

Affected packages and fixed versions:
- nimiq-consensus (crates.io): affected all versions up to 1.2.2; no fix listed
- nimiq-consensus (crates.io): affected all versions up to 1.2.2; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34069/ (Markdown: https://insights.sbomify.com/CVE-2026-34069/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34069
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34069
- OSV: https://osv.dev/vulnerability/CVE-2026-34069

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34069/
Summaries are generated and may contain mistakes; the official description above is the record.