# GHSA-585q-cm62-757j: Segmentation fault and invalid memory read in `mnl::cb_run`

> An attacker can cause a segmentation fault or read unmapped memory by sending a malformed Netlink message to applications using the mnl library.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2025
- **Also known as:** RUSTSEC-2025-0142

## What is GHSA-585q-cm62-757j?

GHSA-585q-cm62-757j is a vulnerability in mnl, published on 18 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The function `mnl::cb_run` is marked as safe but exhibits unsound behavior when processing malformed Netlink message buffers.

Passing a crafted byte slice to `mnl::cb_run` can trigger memory violations. The function does not sufficiently validate the input buffer structure before processing, leading to out-of-bounds reads.

This vulnerability allows an attacker to cause a Denial of Service (segmentation fault) or potentially read unmapped memory by providing a malformed Netlink message.

The underlying issue is a bug in `libmnl` where during validation `nlh->nlmsg_len` is cast to an `int` and becomes negative if `nlmsg_len` is greater than `INT_MAX`. This causes the validation to succeed even if the buffer is too small for the message. This has been fixed in `libmnl` but still affects version 1.0.5.

The issue in `mnl` was fixed in commit `cd51bdc` by checking the validity of netlink messages passed to `mnl::cb_run`.

## Which versions are affected by GHSA-585q-cm62-757j?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mnl` | crates.io | All versions | 0.3.1 |
| `mnl` | crates.io | All versions | 0.3.1 |
| `mnl` | crates.io | From 0.0.0-0 | 0.3.1 |

## How do I fix GHSA-585q-cm62-757j?

Upgrade mnl to 0.3.1 or later.

## Is GHSA-585q-cm62-757j being exploited?

There is no known exploitation of GHSA-585q-cm62-757j in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-585q-cm62-757j and fix it if it is affected.

What it is: GHSA-585q-cm62-757j is a vulnerability in mnl, published on 18 Oct 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-585q-cm62-757j in the wild and no public exploit code.

Affected packages and fixed versions:
- mnl (crates.io): affected all versions; fixed in 0.3.1
- mnl (crates.io): affected all versions; fixed in 0.3.1
- mnl (crates.io): affected from 0.0.0-0; fixed in 0.3.1

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-585q-cm62-757j/ (Markdown: https://insights.sbomify.com/GHSA-585q-cm62-757j/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-585q-cm62-757j

---
From sbomify Insights: https://insights.sbomify.com/GHSA-585q-cm62-757j/
Summaries are generated and may contain mistakes; the official description above is the record.