# CVE-2023-53840: usb: early: xhci-dbc: Fix a potential out-of-bound memory access

> A missing null terminator in the Linux kernel xhci-dbc driver can cause out-of-bounds memory access, potentially leading to crashes or code execution.

- **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:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53840, DEBIAN-CVE-2023-53840, GHSA-x48h-3p3j-rpqg, ROOT-OS-DEBIAN-11-CVE-2023-53840, UBUNTU-CVE-2023-53840

## What is CVE-2023-53840?

CVE-2023-53840 is a memory corruption vulnerability in Linux, published on 9 Dec 2025. 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:

usb: early: xhci-dbc: Fix a potential out-of-bound memory access

If xdbc_bulk_write() fails, the values in 'buf' can be anything. So the
string is not guaranteed to be NULL terminated when xdbc_trace() is called.

Reserve an extra byte, which will be zeroed automatically because 'buf' is
a static variable, in order to avoid troubles, should it happen.

## Which versions are affected by CVE-2023-53840?


## How do I fix CVE-2023-53840?

Apply the vendor's patch.

## Is CVE-2023-53840 being exploited?

There is no known exploitation of CVE-2023-53840 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53840 and fix it if it is affected.

What it is: CVE-2023-53840 is a memory corruption vulnerability in Linux, published on 9 Dec 2025. 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-2023-53840 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-2023-53840/ (Markdown: https://insights.sbomify.com/CVE-2023-53840/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53840
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53840
- OSV: https://osv.dev/vulnerability/CVE-2023-53840

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53840/
Summaries are generated and may contain mistakes; the official description above is the record.