# CVE-2023-3867: ksmbd: fix out of bounds read in smb2_sess_setup

> An out-of-bounds read in the Linux kernel's ksmbd module allows attackers to cause denial of service or disclose sensitive memory contents.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Aug 2025
- **Updated:** 15 Aug 2026
- **Also known as:** BELL-CVE-2023-3867, DEBIAN-CVE-2023-3867, GHSA-pm54-8x3h-h6h9, UBUNTU-CVE-2023-3867

## What is CVE-2023-3867?

CVE-2023-3867 is a critical memory corruption vulnerability in Linux kernel, published on 16 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

ksmbd: fix out of bounds read in smb2_sess_setup

ksmbd does not consider the case of that smb2 session setup is
in compound request. If this is the second payload of the compound,
OOB read issue occurs while processing the first payload in
the smb2_sess_setup().

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2023-3867?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-3867?

Apply the vendor's patch.

## Is CVE-2023-3867 being exploited?

There is no known exploitation of CVE-2023-3867 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-3867 and fix it if it is affected.

What it is: CVE-2023-3867 is a critical memory corruption vulnerability in Linux kernel, published on 16 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-3867 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2023-3867/ (Markdown: https://insights.sbomify.com/CVE-2023-3867/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3867
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3867
- OSV: https://osv.dev/vulnerability/CVE-2023-3867

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-3867/
Summaries are generated and may contain mistakes; the official description above is the record.