# CVE-2026-23174: nvme-pci: handle changing device dma map requirements

> A NULL dereference in the Linux kernel NVMe driver can cause a denial of service when DMA mapping requirements change during iteration.

- **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:** 14 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23174, DEBIAN-CVE-2026-23174, GHSA-wrw7-63r4-jj3j, UBUNTU-CVE-2026-23174

## What is CVE-2026-23174?

CVE-2026-23174 is a vulnerability in Linux, published on 14 Feb 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:

nvme-pci: handle changing device dma map requirements

The initial state of dma_needs_unmap may be false, but change to true
while mapping the data iterator. Enabling swiotlb is one such case that
can change the result. The nvme driver needs to save the mapped dma
vectors to be unmapped later, so allocate as needed during iteration
rather than assume it was always allocated at the beginning. This fixes
a NULL dereference from accessing an uninitialized dma_vecs when the
device dma unmapping requirements change mid-iteration.

## Which versions are affected by CVE-2026-23174?


## How do I fix CVE-2026-23174?

Apply the vendor's patch.

## Is CVE-2026-23174 being exploited?

There is no known exploitation of CVE-2026-23174 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23174 and fix it if it is affected.

What it is: CVE-2026-23174 is a vulnerability in Linux, published on 14 Feb 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-2026-23174 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-2026-23174/ (Markdown: https://insights.sbomify.com/CVE-2026-23174/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23174
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23174
- OSV: https://osv.dev/vulnerability/CVE-2026-23174

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23174/
Summaries are generated and may contain mistakes; the official description above is the record.