# CVE-2026-99113: ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** AZL-111206, BELL-CVE-2026-99113, DEBIAN-CVE-2026-99113, GHSA-3hcx-97mc-6xww, UBUNTU-CVE-2026-99113

## What is CVE-2026-99113?

CVE-2026-99113 is a vulnerability in Linux, published on 28 Oct 2026. 

### Official description

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

ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in

smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION,
that is the whole of struct object_id_info, but writes only 46 of them:

 - objid[] is 16 bytes, and when the volume UUID is not available only
   sizeof(stfs.f_fsid) (8) bytes are copied into it;
 - extended_info.version_string[] is STRING_LENGTH (28) bytes, and only
   strlen("1.1.0") (5) bytes are copied into it.

The response buffer is zeroed on allocation (kvzalloc() in
smb2_allocate_rsp_buf()), so for a standalone request the remaining 31
bytes are zero.  In a compound request they need not be.  The offset of
the next response is advanced by the length pinned for the previous one,
so if a preceding command wrote its reply into the buffer and then
failed, smb2_set_err_rsp() pins only the short error response and the
next reply lands inside the area that has already been written.  Only
the header is cleared there:

	memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);

The client then receives up to 31 bytes of a response it was not meant
to see, including one that failed with an access denied error.

Clear the structure before filling it in.  As a side effect
version_string is now NUL terminated.

## Which versions are affected by CVE-2026-99113?


## How do I fix CVE-2026-99113?

Upgrade to a fixed version.

## Is CVE-2026-99113 being exploited?

There is no known exploitation of CVE-2026-99113 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99113 and fix it if it is affected.

What it is: CVE-2026-99113 is a vulnerability in Linux, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99113 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-2026-99113/ (Markdown: https://insights.sbomify.com/CVE-2026-99113/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99113
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99113
- OSV: https://osv.dev/vulnerability/CVE-2026-99113

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99113/
Summaries are generated and may contain mistakes; the official description above is the record.