# libcrux incorrectly calculates on aarch64

Advisory record · `GHSA-2cgv-28vr-rv6j`

- **Identifiers:** `GHSA-2cgv-28vr-rv6j` · `RUSTSEC-2025-0133`
- **State:** Confirmed
- **Severity:** CVSS 4.0, no score published
- **Critical:** No
- **Weakness (CWE):** [CWE-200](https://cwe.mitre.org/data/definitions/200.html) · [CWE-327](https://cwe.mitre.org/data/definitions/327.html)
- **Tags:** [Information disclosure](https://agentprime.io/advisories/tag/info-disclosure.md) · [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 4 Dec 2025
- **Updated:** 22 Feb 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 4 Dec 2025, 17:24 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `libcrux-intrinsics` (crates.io): affected `>=0.0.3, <0.0.4`; fixed in `0.0.4`
- `libcrux-ml-kem` (crates.io): affected `>=0.0.3, <0.0.4`; fixed in `0.0.4`
- `libcrux-ml-dsa` (crates.io): affected `>=0.0.3, <0.0.4`; fixed in `0.0.4`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Affected versions of libcrux-intrinsics, libcrux-ml-kem and libcrux-ml-dsa from 0.0.3 up to but not including 0.0.4 are affected. On platforms lacking the vxarq_u64 aarch64 intrinsic, an unverified fallback in libcrux-intrinsics produced wrong SHA-3 results, causing libcrux-ml-kem and libcrux-ml-dsa to yield incorrect shared secrets and invalid signatures. The source does not describe attacker requirements. Upgrade all three packages to 0.0.4.

Written 8 Nov 2026.

## 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

- Score not published, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** No score.

## Timeline

- 31 Oct 2026, 15:19 UTC: First seen by agentprime
- 31 Oct 2026, 15:19 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-2cgv-28vr-rv6j)

## Sources

- [GitHub Advisory Database: GHSA-2cgv-28vr-rv6j](https://github.com/advisories/GHSA-2cgv-28vr-rv6j)
- [OSV: GHSA-2cgv-28vr-rv6j](https://osv.dev/vulnerability/GHSA-2cgv-28vr-rv6j)
- <https://github.com/cryspen/libcrux/issues/1220>
- <https://github.com/cryspen/libcrux/pull/1222>
- <https://github.com/cryspen/libcrux/commit/8d10f45631afd1d93fabb2278dbb388a075b5608>
- <https://github.com/cryspen/libcrux>
- <https://rustsec.org/advisories/RUSTSEC-2025-0133.html>

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-2cgv-28vr-rv6j>, 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-2cgv-28vr-rv6j/>. Everything for agents: <https://agentprime.io/llms.txt>.