# CVE-2026-23237: platform/x86: classmate-laptop: Add missing NULL pointer checks

> A missing NULL pointer check in the Linux kernel Classmate laptop driver allows local attackers to cause a system crash by accessing sysfs attributes prematurely.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 4 Mar 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-23237, DEBIAN-CVE-2026-23237, GHSA-9438-9qfw-m4v5, ROOT-OS-DEBIAN-11-CVE-2026-23237, ROOT-OS-DEBIAN-12-CVE-2026-23237, ROOT-OS-DEBIAN-13-CVE-2026-23237, ROOT-OS-UBUNTU-2204-CVE-2026-23237, ROOT-OS-UBUNTU-2404-CVE-2026-23237, UBUNTU-CVE-2026-23237

## What is CVE-2026-23237?

CVE-2026-23237 is a medium-severity vulnerability in Linux kernel, published on 4 Mar 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:

platform/x86: classmate-laptop: Add missing NULL pointer checks

In a few places in the Classmate laptop driver, code using the accel
object may run before that object's address is stored in the driver
data of the input device using it.

For example, cmpc_accel_sensitivity_store_v4() is the "show" method
of cmpc_accel_sensitivity_attr_v4 which is added in cmpc_accel_add_v4(),
before calling dev_set_drvdata() for inputdev->dev.  If the sysfs
attribute is accessed prematurely, the dev_get_drvdata(&inputdev->dev)
call in in cmpc_accel_sensitivity_store_v4() returns NULL which
leads to a NULL pointer dereference going forward.

Moreover, sysfs attributes using the input device are added before
initializing that device by cmpc_add_acpi_notify_device() and if one
of them is accessed before running that function, a NULL pointer
dereference will occur.

For example, cmpc_accel_sensitivity_attr_v4 is added before calling
cmpc_add_acpi_notify_device() and if it is read prematurely, the
dev_get_drvdata(&acpi->dev) call in cmpc_accel_sensitivity_show_v4()
returns NULL which leads to a NULL pointer dereference going forward.

Fix this by adding NULL pointer checks in all of the relevant places.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-23237?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23237?

Apply the vendor's patch.

## Is CVE-2026-23237 being exploited?

There is no known exploitation of CVE-2026-23237 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23237 and fix it if it is affected.

What it is: CVE-2026-23237 is a medium-severity vulnerability in Linux kernel, published on 4 Mar 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-2026-23237 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-23237/ (Markdown: https://insights.sbomify.com/CVE-2026-23237/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23237
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23237
- OSV: https://osv.dev/vulnerability/CVE-2026-23237

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23237/
Summaries are generated and may contain mistakes; the official description above is the record.