# CVE-2026-28402: nimiq/core-rs-albatross's nimiq-blockchain missing proposal body root verification

> A malicious validator can crash other validator nodes by publishing macro block proposals with mismatched body roots, requiring an upgrade to fix.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Feb 2026
- **Updated:** 3 Mar 2026
- **Also known as:** GHSA-7wh6-rmxx-ww47

## What is CVE-2026-28402?

CVE-2026-28402 is a high-severity denial of service vulnerability in nimiq core-rs-albatross, published on 27 Feb 2026. Any signed-in user can exploit it over the network, 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 1.2.2, a malicious or compromised validator that is elected as proposer can publish a macro block proposal where `header.body_root` does not match the actual macro body hash. The proposal can pass proposal verification because the macro proposal verification path validates the header but does not validate the binding `body_root == hash(body)`; later code expects this binding and may panic on mismatch, crashing validators. Note that the impact is only for validator nodes. The patch for this vulnerability is formally released as part of v1.2.2. The patch adds the corresponding body root verification in the proposal checks. No known workarounds are available.

Weakness: CWE-354 (Improper Validation of Integrity Check Value)

## Which versions are affected by CVE-2026-28402?

It affects 1 product.


Products: Nimiq Nimiq Proof-of-Stake.

## How do I fix CVE-2026-28402?

No fix has been published for CVE-2026-28402 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-28402 being exploited?

There is no known exploitation of CVE-2026-28402 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-2026-28402 and fix it if it is affected.

What it is: CVE-2026-28402 is a high-severity denial of service vulnerability in nimiq core-rs-albatross, published on 27 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-28402 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-2026-28402/ (Markdown: https://insights.sbomify.com/CVE-2026-28402/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28402
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28402
- OSV: https://osv.dev/vulnerability/CVE-2026-28402

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28402/
Summaries are generated and may contain mistakes; the official description above is the record.