# CVE-2023-53200: netfilter: x_tables: fix percpu counter block leak on error path when creating new netns

> A memory leak in the Linux kernel netfilter subsystem can lead to resource exhaustion and denial of service when creating new network namespaces.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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:** 15 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53200, DEBIAN-CVE-2023-53200, GHSA-hrpg-229c-xmmq, ROOT-OS-DEBIAN-11-CVE-2023-53200, UBUNTU-CVE-2023-53200

## What is CVE-2023-53200?

CVE-2023-53200 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 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:

netfilter: x_tables: fix percpu counter block leak on error path when creating new netns

Here is the stack where we allocate percpu counter block:

  +-< __alloc_percpu
    +-< xt_percpu_counter_alloc
      +-< find_check_entry # {arp,ip,ip6}_tables.c
        +-< translate_table

And it can be leaked on this code path:

  +-> ip6t_register_table
    +-> translate_table # allocates percpu counter block
    +-> xt_register_table # fails

there is no freeing of the counter block on xt_register_table fail.
Note: xt_percpu_counter_free should be called to free it like we do in
do_replace through cleanup_entry helper (or in __ip6t_unregister_table).

Probability of hitting this error path is low AFAICS (xt_register_table
can only return ENOMEM here, as it is not replacing anything, as we are
creating new netns, and it is hard to imagine that all previous
allocations succeeded and after that one in xt_register_table failed).
But it's worth fixing even the rare leak.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2023-53200?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53200?

Apply the vendor's patch.

## Is CVE-2023-53200 being exploited?

There is no known exploitation of CVE-2023-53200 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-2023-53200 and fix it if it is affected.

What it is: CVE-2023-53200 is a medium-severity denial of service vulnerability in Linux kernel, published on 15 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-2023-53200 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-2023-53200/ (Markdown: https://insights.sbomify.com/CVE-2023-53200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53200
- OSV: https://osv.dev/vulnerability/CVE-2023-53200

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53200/
Summaries are generated and may contain mistakes; the official description above is the record.