# CVE-2023-6817: Use-after-free in Linux kernel's netfilter: nf_tables component

> A use-after-free in the Linux kernel netfilter component allows local attackers to escalate privileges.

- **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:** 18 Dec 2023
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-62609, BELL-CVE-2023-6817, DEBIAN-CVE-2023-6817, GHSA-j5r4-2mjg-6xcc, UBUNTU-CVE-2023-6817

## What is CVE-2023-6817?

CVE-2023-6817 is a high-severity use after free vulnerability in Linux kernel, published on 18 Dec 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation.

The function nft_pipapo_walk did not skip inactive elements during set walk which could lead double deactivations of PIPAPO (Pile Packet Policies) elements, leading to use-after-free.

We recommend upgrading past commit 317eb9685095678f2c9f5a8189de698c5354316a.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2023-6817?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-6817?

Apply the vendor's patch.

## Is CVE-2023-6817 being exploited?

There is no known exploitation of CVE-2023-6817 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-2023-6817 and fix it if it is affected.

What it is: CVE-2023-6817 is a high-severity use after free vulnerability in Linux kernel, published on 18 Dec 2023. 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-2023-6817 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-2023-6817/ (Markdown: https://insights.sbomify.com/CVE-2023-6817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6817
- OSV: https://osv.dev/vulnerability/CVE-2023-6817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-6817/
Summaries are generated and may contain mistakes; the official description above is the record.