# GHSA-hhw4-xg65-fp2x: serde_yml crate is unsound and unmaintained

> Unsoundness in serde_yml can cause segmentation faults, leading to denial of service; users should switch to maintained alternatives.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Sep 2025
- **Also known as:** RUSTSEC-2025-0068

## What is GHSA-hhw4-xg65-fp2x?

GHSA-hhw4-xg65-fp2x is a memory corruption vulnerability in serde_yml, published on 11 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Using `serde_yml::ser::Serializer.emitter` can cause a segmentation fault, which is unsound.

The GitHub project for `serde_yml` was archived after unsoundness issues were raised.

If you rely on this crate, it is highly recommended switching to a maintained alternative.

## Recommended alternatives

- [`serde_norway`](https://crates.io/crates/serde_norway) - Maintained fork of `serde_yaml`, using `unsafe-libyaml-norway`
- [`serde_yaml_ng`](https://crates.io/crates/serde_yaml_ng) - Maintained fork of `serde_yaml`, using unmaintained `unsafe-libyaml`

## Incomplete pure Rust alternatives

These implementation do not rely on C `libyaml`.

- [`serde_yaml2`](https://crates.io/crates/serde_yaml2)
- [`yaml-peg`](https://crates.io/crates/yaml-peg)

## Which versions are affected by GHSA-hhw4-xg65-fp2x?

3 open source packages ship an affected version, including serde_yml.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `serde_yml` | crates.io | All versions to 0.0.12 | None |
| `serde_yml` | crates.io | All versions to 0.0.12 | None |
| `serde_yml` | crates.io | From 0.0.0-0 | None |

## How do I fix GHSA-hhw4-xg65-fp2x?

No fix has been published for GHSA-hhw4-xg65-fp2x yet. Limit exposure of the affected software until one is available.

## Is GHSA-hhw4-xg65-fp2x being exploited?

There is no known exploitation of GHSA-hhw4-xg65-fp2x in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-hhw4-xg65-fp2x and fix it if it is affected.

What it is: GHSA-hhw4-xg65-fp2x is a memory corruption vulnerability in serde_yml, published on 11 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-hhw4-xg65-fp2x in the wild and no public exploit code.

Affected packages and fixed versions:
- serde_yml (crates.io): affected all versions up to 0.0.12; no fix listed
- serde_yml (crates.io): affected all versions up to 0.0.12; no fix listed
- serde_yml (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/GHSA-hhw4-xg65-fp2x/ (Markdown: https://insights.sbomify.com/GHSA-hhw4-xg65-fp2x/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-hhw4-xg65-fp2x

---
From sbomify Insights: https://insights.sbomify.com/GHSA-hhw4-xg65-fp2x/
Summaries are generated and may contain mistakes; the official description above is the record.