# CVE-2025-38724: nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()

> A race condition in the Linux kernel NFS server allows attackers to trigger a use-after-free, potentially leading to code execution or privilege escalation.

- **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:** 4 Sep 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-66854, AZL-73839, BELL-CVE-2025-38724, DEBIAN-CVE-2025-38724, GHSA-x8r2-g34h-2v3j, ROOT-OS-DEBIAN-11-CVE-2025-38724, ROOT-OS-DEBIAN-12-CVE-2025-38724, ROOT-OS-UBUNTU-2204-CVE-2025-38724, ROOT-OS-UBUNTU-2404-CVE-2025-38724, UBUNTU-CVE-2025-38724

## What is CVE-2025-38724?

CVE-2025-38724 is a critical use after free vulnerability in Debian Debian Linux, published on 4 Sep 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:

nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()

Lei Lu recently reported that nfsd4_setclientid_confirm() did not check
the return value from get_client_locked(). a SETCLIENTID_CONFIRM could
race with a confirmed client expiring and fail to get a reference. That
could later lead to a UAF.

Fix this by getting a reference early in the case where there is an
extant confirmed client. If that fails then treat it as if there were no
confirmed client found at all.

In the case where the unconfirmed client is expiring, just fail and
return the result from get_client_locked().

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-38724?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38724?

Apply the vendor's patch.

## Is CVE-2025-38724 being exploited?

There is no known exploitation of CVE-2025-38724 in the wild and no public exploit code.

## 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-2025-38724 and fix it if it is affected.

What it is: CVE-2025-38724 is a critical use after free vulnerability in Debian Debian Linux, published on 4 Sep 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-2025-38724 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-2025-38724/ (Markdown: https://insights.sbomify.com/CVE-2025-38724/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38724
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38724
- OSV: https://osv.dev/vulnerability/CVE-2025-38724

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38724/
Summaries are generated and may contain mistakes; the official description above is the record.