# RUSTSEC-2026-0164: `pqcrypto` is unmaintained: upstream PQClean project being archived

> The pqcrypto library is unmaintained due to upstream archival, requiring users to migrate to actively maintained alternatives to ensure security.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not stated
- **Attackable:** Not stated
- **Victim action needed:** Not stated
- **Fix available:** No
- **Published:** 4 Jun 2026

## What is RUSTSEC-2026-0164?

RUSTSEC-2026-0164 is a vulnerability in pqcrypto, published on 4 Jun 2026. 

### Official description

The `pqcrypto` crate and the entire `pqcrypto-*` ecosystem wrap C implementations
from [PQClean](https://github.com/PQClean/PQClean). The PQClean project is being
archived in or after July 2026 (see [PQClean/PQClean#604](https://github.com/PQClean/PQClean/issues/604)),
after which no further security patches, algorithm updates, or bug fixes will
be applied to the upstream implementations.

As a result, this crate and all dependent crates in the `pqcrypto-*` ecosystem
will no longer receive updates. Users should migrate to actively maintained
alternatives. Pure-Rust replacements are available for several algorithms:

- ML-KEM (FIPS 203): [`ml-kem`](https://crates.io/crates/ml-kem)
- ML-DSA (FIPS 204): [`ml-dsa`](https://crates.io/crates/ml-dsa)
- SLH-DSA (FIPS 205): [`slh-dsa`](https://crates.io/crates/slh-dsa)
- FN-DSA (FIPS 206): [`fn-dsa`](https://crates.io/crates/fn-dsa)

## Which versions are affected by RUSTSEC-2026-0164?

1 open source package ship an affected version, including pqcrypto.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pqcrypto` | crates.io | From 0.0.0-0 | None |

## How do I fix RUSTSEC-2026-0164?

No fix has been published for RUSTSEC-2026-0164 yet. Limit exposure of the affected software until one is available.

## Is RUSTSEC-2026-0164 being exploited?

There is no known exploitation of RUSTSEC-2026-0164 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for RUSTSEC-2026-0164 and fix it if it is affected.

What it is: RUSTSEC-2026-0164 is a vulnerability in pqcrypto, published on 4 Jun 2026. 
Exploitation: There is no known exploitation of RUSTSEC-2026-0164 in the wild and no public exploit code.

Affected packages and fixed versions:
- pqcrypto (crates.io): affected from 0.0.0-0; no fix listed

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/RUSTSEC-2026-0164/ (Markdown: https://insights.sbomify.com/RUSTSEC-2026-0164/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/RUSTSEC-2026-0164

---
From sbomify Insights: https://insights.sbomify.com/RUSTSEC-2026-0164/
Summaries are generated and may contain mistakes; the official description above is the record.