# CVE-2026-89794: ksmbd: zero pipe read compound padding

> An attacker can read uninitialized kernel heap memory via ksmbd pipe read compound padding, potentially exposing sensitive data.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101355, BELL-CVE-2026-89794, DEBIAN-CVE-2026-89794, GHSA-69w5-4c2f-pfhh, UBUNTU-CVE-2026-89794

## What is CVE-2026-89794?

CVE-2026-89794 is a vulnerability in Linux, published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: zero pipe read compound padding

Compound response handling extends the last response iov to an eight-byte
boundary.

smb2_read_pipe() allocates only the payload size, so the alignment padding
can expose up to seven bytes of uninitialized kernel heap memory.

Allocate the aligned size and clear the unused tail before pinning the
response buffer.

## Which versions are affected by CVE-2026-89794?


## How do I fix CVE-2026-89794?

Apply the vendor's patch.

## Is CVE-2026-89794 being exploited?

There is no known exploitation of CVE-2026-89794 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89794 and fix it if it is affected.

What it is: CVE-2026-89794 is a vulnerability in Linux, published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-89794 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-2026-89794/ (Markdown: https://insights.sbomify.com/CVE-2026-89794/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89794
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89794
- OSV: https://osv.dev/vulnerability/CVE-2026-89794

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89794/
Summaries are generated and may contain mistakes; the official description above is the record.