# CVE-2025-38571: sunrpc: fix client side handling of tls alerts

> A null pointer dereference in the Linux kernel's NFS over TLS client allows attackers to cause a denial of service via crafted TLS alerts.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:** 19 Aug 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-66467, BELL-CVE-2025-38571, DEBIAN-CVE-2025-38571, GHSA-r3wq-5xjj-hj39, ROOT-OS-DEBIAN-13-CVE-2025-38571, ROOT-OS-UBUNTU-2404-CVE-2025-38571, UBUNTU-CVE-2025-38571

## What is CVE-2025-38571?

CVE-2025-38571 is a high-severity vulnerability in Linux kernel, 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:

sunrpc: fix client side handling of tls alerts

A security exploit was discovered in NFS over TLS in tls_alert_recv
due to its assumption that there is valid data in the msghdr's
iterator's kvec.

Instead, this patch proposes the rework how control messages are
setup and used by sock_recvmsg().

If no control message structure is setup, kTLS layer will read and
process TLS data record types. As soon as it encounters a TLS control
message, it would return an error. At that point, NFS can setup a kvec
backed control buffer and read in the control message such as a TLS
alert. Scott found that a msg iterator can advance the kvec pointer
as a part of the copy process thus we need to revert the iterator
before calling into the tls_alert_recv.

## Which versions are affected by CVE-2025-38571?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38571?

Apply the vendor's patch.

## Is CVE-2025-38571 being exploited?

There is no known exploitation of CVE-2025-38571 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-2025-38571 and fix it if it is affected.

What it is: CVE-2025-38571 is a high-severity vulnerability in Linux kernel, 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-2025-38571 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-2025-38571/ (Markdown: https://insights.sbomify.com/CVE-2025-38571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38571
- OSV: https://osv.dev/vulnerability/CVE-2025-38571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38571/
Summaries are generated and may contain mistakes; the official description above is the record.