# CVE-2026-53000: netfilter: nat: use kfree_rcu to release ops

> A use-after-free vulnerability in the Linux kernel netfilter NAT module allows attackers to potentially execute code or escalate privileges via improper memory release.

- **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:** 24 Jun 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-90372, BELL-CVE-2026-53000, DEBIAN-CVE-2026-53000, GHSA-6794-4vqv-w8qg, ROOT-OS-DEBIAN-12-CVE-2026-53000, ROOT-OS-DEBIAN-13-CVE-2026-53000, ROOT-OS-UBUNTU-2204-CVE-2026-53000, ROOT-OS-UBUNTU-2404-CVE-2026-53000, UBUNTU-CVE-2026-53000

## What is CVE-2026-53000?

CVE-2026-53000 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 2026. 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: nat: use kfree_rcu to release ops

Florian Westphal says:

"Historically this is not an issue, even for normal base hooks: the data
path doesn't use the original nf_hook_ops that are used to register the
callbacks.

However, in v5.14 I added the ability to dump the active netfilter
hooks from userspace.

This code will peek back into the nf_hook_ops that are available
at the tail of the pointer-array blob used by the datapath.

The nat hooks are special, because they are called indirectly from
the central nat dispatcher hook. They are currently invisible to
the nfnl hook dump subsystem though.

But once that changes the nat ops structures have to be deferred too."

Update nf_nat_register_fn() to deal with partial exposition of the hooks
from error path which can be also an issue for nfnetlink_hook.

Weakness: CWE-763 (Release of Invalid Pointer or Reference)

## Which versions are affected by CVE-2026-53000?

It affects 2 products.


Products: Linux kernel, Redhat Enterprise Linux.

## How do I fix CVE-2026-53000?

Apply the vendor's patch.

## Is CVE-2026-53000 being exploited?

There is no known exploitation of CVE-2026-53000 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-2026-53000 and fix it if it is affected.

What it is: CVE-2026-53000 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 2026. 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-2026-53000 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-2026-53000/ (Markdown: https://insights.sbomify.com/CVE-2026-53000/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53000
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53000
- OSV: https://osv.dev/vulnerability/CVE-2026-53000

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53000/
Summaries are generated and may contain mistakes; the official description above is the record.