# CVE-2026-93096: cxl/features: Serialize multi-part Get/Set Feature transfers

> A race condition in the Linux kernel CXL feature handling allows concurrent transfers to corrupt device state, potentially causing denial of service or data corruption.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-93096, DEBIAN-CVE-2026-93096, GHSA-gqcj-fh23-47rq, UBUNTU-CVE-2026-93096

## What is CVE-2026-93096?

CVE-2026-93096 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

cxl/features: Serialize multi-part Get/Set Feature transfers

A Get or Set Feature payload larger than the mailbox payload size is
split into several mailbox commands. mbox_mutex only serializes
individual mailbox commands and is dropped between iterations of these
loops. Nothing serializes the multi-part transfer as a whole.
cxl_get_feature() and cxl_set_feature() are reachable concurrently
from fwctl (per-fd RPCs run under a read-held registration lock) and
from the EDAC scrub/ECS/repair paths, so two transfers to the same
mailbox can interleave their parts and corrupt the device's transfer
context.

Add a per-mailbox feat_mutex and hold it across the whole transfer in
both functions. It nests outside mbox_mutex (which is taken inside
cxl_internal_send_cmd()), and is taken nowhere else, so no lock-ordering
inversion is introduced.

## Which versions are affected by CVE-2026-93096?


## How do I fix CVE-2026-93096?

Apply the vendor's patch.

## Is CVE-2026-93096 being exploited?

There is no known exploitation of CVE-2026-93096 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93096 and fix it if it is affected.

What it is: CVE-2026-93096 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93096 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

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/CVE-2026-93096/ (Markdown: https://insights.sbomify.com/CVE-2026-93096/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93096
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93096
- OSV: https://osv.dev/vulnerability/CVE-2026-93096

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93096/
Summaries are generated and may contain mistakes; the official description above is the record.