# nimiq-block has skip block quorum bypass via out-of-range BitSet indices & u16 truncation

Advisory record · `GHSA-6973-8887-87ff`

- **Identifiers:** `GHSA-6973-8887-87ff` · `CVE-2026-33471`
- **State:** Confirmed
- **Severity:** CVSS 9.6 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-20](https://cwe.mitre.org/data/definitions/20.html) · [CWE-190](https://cwe.mitre.org/data/definitions/190.html) · [CWE-345](https://cwe.mitre.org/data/definitions/345.html) · [CWE-1284](https://cwe.mitre.org/data/definitions/1284.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) · [CWE-20](https://agentprime.io/advisories/tag/cwe-20.md) · [CWE-345](https://agentprime.io/advisories/tag/cwe-345.md) · [CWE-1284](https://agentprime.io/advisories/tag/cwe-1284.md)
- **Published:** 22 Apr 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 22 Apr 2026, 19:13 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.6: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `nimiq-block` (crates.io): affected `<1.7.2`; fixed in `1.7.2`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.6 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0022, the 12th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:24 UTC: First seen by agentprime
- 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-6973-8887-87ff)

## Sources

- [GitHub Advisory Database: GHSA-6973-8887-87ff](https://github.com/advisories/GHSA-6973-8887-87ff)
- [OSV: GHSA-6973-8887-87ff](https://osv.dev/vulnerability/GHSA-6973-8887-87ff)
- <https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-6973-8887-87ff>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-33471>
- <https://github.com/nimiq/core-rs-albatross/pull/3657>
- <https://github.com/nimiq/core-rs-albatross/commit/d02059053181ed8ddad6b59a0adfd661ef5cd823>
- <https://github.com/nimiq/core-rs-albatross>
- <https://github.com/nimiq/core-rs-albatross/releases/tag/v1.3.0>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-6973-8887-87ff>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-6973-8887-87ff/>. Everything for agents: <https://agentprime.io/llms.txt>.