# CVE-2025-38561: ksmbd: fix Preauh_HashValue race condition

> A race condition in the Linux kernel's ksmbd module allows attackers to cause a denial of service via multiple session setup requests.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 19 Aug 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-38561, DEBIAN-CVE-2025-38561, GHSA-6mwh-579p-fgpg, ROOT-OS-DEBIAN-11-CVE-2025-38561, ROOT-OS-DEBIAN-12-CVE-2025-38561, ROOT-OS-DEBIAN-13-CVE-2025-38561, ROOT-OS-UBUNTU-2204-CVE-2025-38561, ROOT-OS-UBUNTU-2404-CVE-2025-38561

## What is CVE-2025-38561?

CVE-2025-38561 is a critical vulnerability in Debian Debian Linux, published on 19 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 Preauh_HashValue race condition

If client send multiple session setup requests to ksmbd,
Preauh_HashValue race condition could happen.
There is no need to free sess->Preauh_HashValue at session setup phase.
It can be freed together with session at connection termination phase.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2025-38561?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38561?

Apply the vendor's patch.

## Is CVE-2025-38561 being exploited?

There is no known exploitation of CVE-2025-38561 in the wild and no public exploit code.

Public exploit code:

-  ksmbd: Preauh_HashValue race condition If client send multiple session setup requests to ksmbd, Preauh_HashValue race condition could happen. (github_poc): https://github.com/toshithh/CVE-2025-38561

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38561 and fix it if it is affected.

What it is: CVE-2025-38561 is a critical vulnerability in Debian Debian Linux, published on 19 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-2025-38561 in the wild and no public exploit code.

Affected product: Debian Debian 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-2025-38561/ (Markdown: https://insights.sbomify.com/CVE-2025-38561/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38561
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38561
- OSV: https://osv.dev/vulnerability/CVE-2025-38561

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38561/
Summaries are generated and may contain mistakes; the official description above is the record.