# CVE-2026-93812: ksmbd: fix sd_ndr.data memory leak in ksmbd_vfs_set_sd_xattr

> A memory leak in the Linux kernel's ksmbd module allows attackers to cause a denial of service by triggering encoding errors.

- **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:** 24 Sep 2026
- **Updated:** 3 Oct 2026
- **Also known as:** AZL-103949, BELL-CVE-2026-93812, DEBIAN-CVE-2026-93812, GHSA-7f3p-w572-qm2q, UBUNTU-CVE-2026-93812

## What is CVE-2026-93812?

CVE-2026-93812 is a denial of service vulnerability in Linux, published on 24 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: fix sd_ndr.data memory leak in ksmbd_vfs_set_sd_xattr

ndr_encode_v4_ntacl() allocates sd_ndr.data via kzalloc() at entry.
If any subsequent ndr_write_*() call returns error during encoding,
the allocated sd_ndr.data won't be freed and causes memory leak.

Move kfree(sd_ndr.data) into out label to ensure the buffer gets
released on all success and error return paths.

## Which versions are affected by CVE-2026-93812?


## How do I fix CVE-2026-93812?

Apply the vendor's patch.

## Is CVE-2026-93812 being exploited?

There is no known exploitation of CVE-2026-93812 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93812 and fix it if it is affected.

What it is: CVE-2026-93812 is a denial of service vulnerability in Linux, published on 24 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-2026-93812 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-2026-93812/ (Markdown: https://insights.sbomify.com/CVE-2026-93812/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93812
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93812
- OSV: https://osv.dev/vulnerability/CVE-2026-93812

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93812/
Summaries are generated and may contain mistakes; the official description above is the record.