# CVE-2023-54200: netfilter: nf_tables: always release netdev hooks from notifier

> A use-after-free vulnerability in the Linux kernel netfilter subsystem allows attackers to cause a denial of service or potentially execute code via crafted network namespace removal sequences.

- **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:** 30 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-54200, DEBIAN-CVE-2023-54200, GHSA-jgcg-mpfg-g663, UBUNTU-CVE-2023-54200

## What is CVE-2023-54200?

CVE-2023-54200 is a high-severity use after free vulnerability in Linux, published on 30 Dec 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: nf_tables: always release netdev hooks from notifier

This reverts "netfilter: nf_tables: skip netdev events generated on netns removal".

The problem is that when a veth device is released, the veth release
callback will also queue the peer netns device for removal.

Its possible that the peer netns is also slated for removal.  In this
case, the device memory is already released before the pre_exit hook of
the peer netns runs:

BUG: KASAN: slab-use-after-free in nf_hook_entry_head+0x1b8/0x1d0
Read of size 8 at addr ffff88812c0124f0 by task kworker/u8:1/45
Workqueue: netns cleanup_net
Call Trace:
 nf_hook_entry_head+0x1b8/0x1d0
 __nf_unregister_net_hook+0x76/0x510
 nft_netdev_unregister_hooks+0xa0/0x220
 __nft_release_hook+0x184/0x490
 nf_tables_pre_exit_net+0x12f/0x1b0
 ..

Order is:
1. First netns is released, veth_dellink() queues peer netns device
   for removal
2. peer netns is queued for removal
3. peer netns device is released, unreg event is triggered
4. unreg event is ignored because netns is going down
5. pre_exit hook calls nft_netdev_unregister_hooks but device memory
   might be free'd already.

## Which versions are affected by CVE-2023-54200?


## How do I fix CVE-2023-54200?

Apply the vendor's patch.

## Is CVE-2023-54200 being exploited?

There is no known exploitation of CVE-2023-54200 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54200 and fix it if it is affected.

What it is: CVE-2023-54200 is a high-severity use after free vulnerability in Linux, published on 30 Dec 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-2023-54200 in the wild and no public exploit code.

Affected product: 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-2023-54200/ (Markdown: https://insights.sbomify.com/CVE-2023-54200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54200
- OSV: https://osv.dev/vulnerability/CVE-2023-54200

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54200/
Summaries are generated and may contain mistakes; the official description above is the record.