# CVE-2025-68797: char: applicom: fix NULL pointer dereference in ac_ioctl

> A local attacker can cause a denial of service via a NULL pointer dereference in the applicom character driver when using a specific ioctl command.

- **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:** 13 Jan 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-74459, BELL-CVE-2025-68797, DEBIAN-CVE-2025-68797, GHSA-rm79-9rvw-rjv2, ROOT-OS-DEBIAN-11-CVE-2025-68797, ROOT-OS-DEBIAN-12-CVE-2025-68797, ROOT-OS-DEBIAN-13-CVE-2025-68797, ROOT-OS-UBUNTU-2204-CVE-2025-68797, ROOT-OS-UBUNTU-2404-CVE-2025-68797, UBUNTU-CVE-2025-68797

## What is CVE-2025-68797?

CVE-2025-68797 is a vulnerability in Linux, published on 13 Jan 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:

char: applicom: fix NULL pointer dereference in ac_ioctl

Discovered by Atuin - Automated Vulnerability Discovery Engine.

In ac_ioctl, the validation of IndexCard and the check for a valid
RamIO pointer are skipped when cmd is 6. However, the function
unconditionally executes readb(apbs[IndexCard].RamIO + VERS) at the
end.

If cmd is 6, IndexCard may reference a board that does not exist
(where RamIO is NULL), leading to a NULL pointer dereference.

Fix this by skipping the readb access when cmd is 6, as this
command is a global information query and does not target a specific
board context.

## Which versions are affected by CVE-2025-68797?


## How do I fix CVE-2025-68797?

Apply the vendor's patch.

## Is CVE-2025-68797 being exploited?

There is no known exploitation of CVE-2025-68797 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68797 and fix it if it is affected.

What it is: CVE-2025-68797 is a vulnerability in Linux, published on 13 Jan 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-2025-68797 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-2025-68797/ (Markdown: https://insights.sbomify.com/CVE-2025-68797/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68797
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68797
- OSV: https://osv.dev/vulnerability/CVE-2025-68797

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68797/
Summaries are generated and may contain mistakes; the official description above is the record.