# CVE-2026-63967: iio: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer

> A local attacker can read uninitialized kernel stack memory via the ST LSM6DSX IMU driver's tagged FIFO interface, potentially exposing sensitive data.

- **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:** 19 Jul 2026
- **Updated:** 19 Jul 2026
- **Also known as:** BELL-CVE-2026-63967, DEBIAN-CVE-2026-63967, GHSA-vghm-prgp-x82v, ROOT-OS-UBUNTU-2204-CVE-2026-63967, UBUNTU-CVE-2026-63967

## What is CVE-2026-63967?

CVE-2026-63967 is a 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: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer

The tagged FIFO path declares iio_buff on the stack with __aligned(8)
but no initializer, but there is a hole in the structure, which will
then leak to userspace as ST_LSM6DSX_SAMPLE_SIZE bytes (6) will be
copied, but the space between that and the timestamp are not
initialized.

Commit c14edb4d0bdc ("iio:imu:st_lsm6dsx Fix alignment and data leak
issues") moved the untagged FIFO path to a kzalloc'd buffer in hw->scan,
but for the tagged path it only added the alignment qualifier and not
the initializer :(

Fix this by just zero-initializing the structure on the stack.

## Which versions are affected by CVE-2026-63967?


## How do I fix CVE-2026-63967?

Apply the vendor's patch.

## Is CVE-2026-63967 being exploited?

There is no known exploitation of CVE-2026-63967 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63967 and fix it if it is affected.

What it is: CVE-2026-63967 is a 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-2026-63967 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-2026-63967/ (Markdown: https://insights.sbomify.com/CVE-2026-63967/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63967
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63967
- OSV: https://osv.dev/vulnerability/CVE-2026-63967

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63967/
Summaries are generated and may contain mistakes; the official description above is the record.