# CVE-2026-63931: iio: chemical: scd30: fix division by zero in write_raw

> A local attacker can cause a kernel crash by writing zero to the sampling frequency sysfs attribute in the SCD30 driver.

- **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:** 19 Jul 2026
- **Updated:** 19 Jul 2026
- **Also known as:** BELL-CVE-2026-63931, DEBIAN-CVE-2026-63931, GHSA-63gc-r7wc-mrxq, ROOT-OS-UBUNTU-2204-CVE-2026-63931, UBUNTU-CVE-2026-63931

## What is CVE-2026-63931?

CVE-2026-63931 is a denial of service vulnerability in Linux, published on 19 Jul 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:

iio: chemical: scd30: fix division by zero in write_raw

Add a zero check for val2 before using it as a divisor when setting the
sampling frequency. A user writing a zero fractional part to the
sampling_frequency sysfs attribute triggers a division by zero in the
kernel.

## Which versions are affected by CVE-2026-63931?


## How do I fix CVE-2026-63931?

Apply the vendor's patch.

## Is CVE-2026-63931 being exploited?

There is no known exploitation of CVE-2026-63931 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63931 and fix it if it is affected.

What it is: CVE-2026-63931 is a denial of service vulnerability in Linux, published on 19 Jul 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-2026-63931 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-2026-63931/ (Markdown: https://insights.sbomify.com/CVE-2026-63931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63931
- OSV: https://osv.dev/vulnerability/CVE-2026-63931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63931/
Summaries are generated and may contain mistakes; the official description above is the record.