# CVE-2023-53549: netfilter: ipset: Rework long task execution when adding/deleting entries

> An attacker can cause a denial of service via soft lockups by adding or deleting large numbers of elements in ipset.

- **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:** 4 Oct 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2023-53549, DEBIAN-CVE-2023-53549, GHSA-ff5r-w44x-rq6x, UBUNTU-CVE-2023-53549

## What is CVE-2023-53549?

CVE-2023-53549 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 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: ipset: Rework long task execution when adding/deleting entries

When adding/deleting large number of elements in one step in ipset, it can
take a reasonable amount of time and can result in soft lockup errors. The
patch 5f7b51bf09ba ("netfilter: ipset: Limit the maximal range of
consecutive elements to add/delete") tried to fix it by limiting the max
elements to process at all. However it was not enough, it is still possible
that we get hung tasks. Lowering the limit is not reasonable, so the
approach in this patch is as follows: rely on the method used at resizing
sets and save the state when we reach a smaller internal batch limit,
unlock/lock and proceed from the saved state. Thus we can avoid long
continuous tasks and at the same time removed the limit to add/delete large
number of elements in one step.

The nfnl mutex is held during the whole operation which prevents one to
issue other ipset commands in parallel.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2023-53549?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53549?

Apply the vendor's patch.

## Is CVE-2023-53549 being exploited?

There is no known exploitation of CVE-2023-53549 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-2023-53549 and fix it if it is affected.

What it is: CVE-2023-53549 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 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-2023-53549 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-2023-53549/ (Markdown: https://insights.sbomify.com/CVE-2023-53549/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53549
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53549
- OSV: https://osv.dev/vulnerability/CVE-2023-53549

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53549/
Summaries are generated and may contain mistakes; the official description above is the record.