# CVE-2026-34062: Nimiq has Allocation of Resources Without Limits or Throttling in its libp2p request/response

> A remote peer can exhaust resources by keeping substreams open, causing denial of service in Nimiq libp2p nodes.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2026
- **Updated:** 23 Apr 2026
- **Also known as:** GHSA-gh7r-qh4p-q4fr

## What is CVE-2026-34062?

CVE-2026-34062 is a medium-severity denial of service vulnerability in nimiq network-libp2p, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

nimiq-libp2p is a Nimiq network implementation based on libp2p. Prior to version 1.3.0, `MessageCodec::read_request` and `read_response` call `read_to_end()` on inbound substreams, so a remote peer can send only a partial frame and keep the substream open. because `Behaviour::new` also sets `with_max_concurrent_streams(1000)`, the node exposes a much larger stalled-slot budget than the library default. The patch for this vulnerability is formally released as part of v1.3.0. No known workarounds are available.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2026-34062?

It affects 1 product.


Products: Nimiq Nimiq Proof-of-Stake.

## How do I fix CVE-2026-34062?

No fix has been published for CVE-2026-34062 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34062 being exploited?

There is no known exploitation of CVE-2026-34062 in the wild and no public exploit code.

## Other vulnerabilities in nimiq network-libp2p

- [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-2026-34062 and fix it if it is affected.

What it is: CVE-2026-34062 is a medium-severity denial of service vulnerability in nimiq network-libp2p, published on 22 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34062 in the wild and no public exploit code.

Affected product: nimiq network-libp2p. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-34062/ (Markdown: https://insights.sbomify.com/CVE-2026-34062/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34062
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34062
- OSV: https://osv.dev/vulnerability/CVE-2026-34062

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34062/
Summaries are generated and may contain mistakes; the official description above is the record.