# CVE-2025-39853: i40e: Fix potential invalid access when MAC list is empty

> A flaw in the i40e network driver allows invalid memory access when the MAC list is empty, potentially causing a system crash.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Sep 2025
- **Updated:** 12 May 2026
- **Also known as:** AZL-67523, AZL-74847, BELL-CVE-2025-39853, DEBIAN-CVE-2025-39853, GHSA-7fp7-xjmp-444h, ROOT-OS-DEBIAN-11-CVE-2025-39853, ROOT-OS-DEBIAN-12-CVE-2025-39853, ROOT-OS-DEBIAN-13-CVE-2025-39853, ROOT-OS-UBUNTU-2204-CVE-2025-39853, ROOT-OS-UBUNTU-2404-CVE-2025-39853, UBUNTU-CVE-2025-39853

## What is CVE-2025-39853?

CVE-2025-39853 is a high-severity vulnerability in Debian Debian Linux, published on 19 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

i40e: Fix potential invalid access when MAC list is empty

list_first_entry() never returns NULL - if the list is empty, it still
returns a pointer to an invalid object, leading to potential invalid
memory access when dereferenced.

Fix this by using list_first_entry_or_null instead of list_first_entry.

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

## Which versions are affected by CVE-2025-39853?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-39853?

Apply the vendor's patch.

## Is CVE-2025-39853 being exploited?

There is no known exploitation of CVE-2025-39853 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-2025-39853 and fix it if it is affected.

What it is: CVE-2025-39853 is a high-severity vulnerability in Debian Debian Linux, published on 19 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-39853 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-2025-39853/ (Markdown: https://insights.sbomify.com/CVE-2025-39853/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39853
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39853
- OSV: https://osv.dev/vulnerability/CVE-2025-39853

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39853/
Summaries are generated and may contain mistakes; the official description above is the record.