# CVE-2026-33184: nimiq/core-rs-albatross: Discovery handshake limit could underflow and later provoke a deterministic overflow panic

> A remote attacker can crash the Nimiq node by sending a zero limit during handshake, causing an integer underflow and subsequent panic.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Apr 2026
- **Updated:** 6 Apr 2026
- **Also known as:** GHSA-5rm9-893q-vmhm

## What is CVE-2026-33184?

CVE-2026-33184 is a high-severity vulnerability in nimiq core-rs-albatross, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

nimiq/core-rs-albatross is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.3.0, the discovery handler accepts a peer-controlled limit during handshake and stores it unchanged. The immediate HandshakeAck path then honors limit = 0 and returns zero contacts, which makes the session look benign. Later, after the same session reaches Established, the periodic update path computes self.peer_list_limit.unwrap() as usize - 1. With limit = 0, that wraps to usize::MAX and then in rand 0.9.2, choose_multiple() immediately attempts Vec::with_capacity(amount), which deterministically panics with capacity overflow. This issue has been patched in version 1.3.0.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-33184?

It affects 1 product.


Products: Nimiq Nimiq Proof-of-Stake.

## How do I fix CVE-2026-33184?

No fix has been published for CVE-2026-33184 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33184 being exploited?

There is no known exploitation of CVE-2026-33184 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-2026-33184 and fix it if it is affected.

What it is: CVE-2026-33184 is a high-severity vulnerability in nimiq core-rs-albatross, published on 3 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-2026-33184 in the wild and no public exploit code.

Affected product: nimiq core-rs-albatross. 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-2026-33184/ (Markdown: https://insights.sbomify.com/CVE-2026-33184/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33184
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33184
- OSV: https://osv.dev/vulnerability/CVE-2026-33184

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33184/
Summaries are generated and may contain mistakes; the official description above is the record.