# CVE-2023-52628: netfilter: nftables: exthdr: fix 4-byte stack OOB write

> A stack out-of-bounds write in the Linux kernel netfilter subsystem allows attackers to corrupt memory, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 28 Mar 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-52628, DEBIAN-CVE-2023-52628, GHSA-6r42-gm3x-9xx3, UBUNTU-CVE-2023-52628

## What is CVE-2023-52628?

CVE-2023-52628 is a high-severity memory corruption vulnerability in Linux kernel, published on 28 Mar 2024. 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: nftables: exthdr: fix 4-byte stack OOB write

If priv->len is a multiple of 4, then dst[len / 4] can write past
the destination array which leads to stack corruption.

This construct is necessary to clean the remainder of the register
in case ->len is NOT a multiple of the register size, so make it
conditional just like nft_payload.c does.

The bug was added in 4.1 cycle and then copied/inherited when
tcp/sctp and ip option support was added.

Bug reported by Zero Day Initiative project (ZDI-CAN-21950,
ZDI-CAN-21951, ZDI-CAN-21961).

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2023-52628?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52628?

Apply the vendor's patch.

## Is CVE-2023-52628 being exploited?

There is no known exploitation of CVE-2023-52628 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-2023-52628 and fix it if it is affected.

What it is: CVE-2023-52628 is a high-severity memory corruption vulnerability in Linux kernel, published on 28 Mar 2024. 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-2023-52628 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-2023-52628/ (Markdown: https://insights.sbomify.com/CVE-2023-52628/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52628
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52628
- OSV: https://osv.dev/vulnerability/CVE-2023-52628

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52628/
Summaries are generated and may contain mistakes; the official description above is the record.