# CVE-2026-93097: cxl/mbox: Break poison list loop on an empty payload

> A malicious CXL device can cause a kernel hang by returning empty poison lists, blocking system operations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **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:** AZL-102980, BELL-CVE-2026-93097, DEBIAN-CVE-2026-93097, GHSA-x7w4-f354-q3xf, UBUNTU-CVE-2026-93097

## What is CVE-2026-93097?

CVE-2026-93097 is a denial of service 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/mbox: Break poison list loop on an empty payload

A device that returns count == 0 with CXL_POISON_FLAG_MORE set on every
iteration never advances nr_records, so the max_errors guard never
trips and the do/while loops forever while holding poison.mutex. That
hangs the sysfs-triggered scan thread and blocks all subsequent poison
operations on the device. The existing "Protect against an uncleared
_FLAG_MORE" guard was intended to bound a misbehaving device but does
not cover the count == 0 case.

Stop the loop on an empty payload so a malfunctioning or malicious
device cannot wedge the poison scan.

## Which versions are affected by CVE-2026-93097?


## How do I fix CVE-2026-93097?

Apply the vendor's patch.

## Is CVE-2026-93097 being exploited?

There is no known exploitation of CVE-2026-93097 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93097 and fix it if it is affected.

What it is: CVE-2026-93097 is a denial of service 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-2026-93097 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-2026-93097/ (Markdown: https://insights.sbomify.com/CVE-2026-93097/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93097
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93097
- OSV: https://osv.dev/vulnerability/CVE-2026-93097

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93097/
Summaries are generated and may contain mistakes; the official description above is the record.