# CVE-2025-38639: netfilter: xt_nfacct: don't assume acct name is null-terminated

> A missing null-termination check in the Linux kernel netfilter module allows out-of-bounds reads, potentially disclosing sensitive memory contents.

- **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:** 22 Aug 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-66617, AZL-73488, BELL-CVE-2025-38639, DEBIAN-CVE-2025-38639, GHSA-44mx-f9p7-87j2, ROOT-OS-DEBIAN-11-CVE-2025-38639, ROOT-OS-DEBIAN-12-CVE-2025-38639, ROOT-OS-DEBIAN-13-CVE-2025-38639, ROOT-OS-UBUNTU-2204-CVE-2025-38639, ROOT-OS-UBUNTU-2404-CVE-2025-38639, UBUNTU-CVE-2025-38639

## What is CVE-2025-38639?

CVE-2025-38639 is a high-severity vulnerability in Debian Debian Linux, published on 22 Aug 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:

netfilter: xt_nfacct: don't assume acct name is null-terminated

BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721
Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851
[..]
 string+0x231/0x2b0 lib/vsprintf.c:721
 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874
 [..]
 nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41
 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523

nfnl_acct_find_get() handles non-null input, but the error
printk relied on its presence.

## Which versions are affected by CVE-2025-38639?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38639?

Apply the vendor's patch.

## Is CVE-2025-38639 being exploited?

There is no known exploitation of CVE-2025-38639 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-2025-38639 and fix it if it is affected.

What it is: CVE-2025-38639 is a high-severity vulnerability in Debian Debian Linux, published on 22 Aug 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-2025-38639 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-2025-38639/ (Markdown: https://insights.sbomify.com/CVE-2025-38639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38639
- OSV: https://osv.dev/vulnerability/CVE-2025-38639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38639/
Summaries are generated and may contain mistakes; the official description above is the record.