# CVE-2026-52920: netfilter: xt_policy: fix strict mode inbound policy matching

> Incorrect strict mode matching in netfilter policy allows bypassing inbound security policies when specific configurations are used.

- **Severity:** High 8.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-52920, DEBIAN-CVE-2026-52920, GHSA-qgcc-gwgq-pq62, ROOT-OS-DEBIAN-11-CVE-2026-52920, ROOT-OS-DEBIAN-12-CVE-2026-52920, ROOT-OS-UBUNTU-2204-CVE-2026-52920, ROOT-OS-UBUNTU-2404-CVE-2026-52920, UBUNTU-CVE-2026-52920

## What is CVE-2026-52920?

CVE-2026-52920 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: xt_policy: fix strict mode inbound policy matching

match_policy_in() walks sec_path entries from the last transform to the
first one, but strict policy matching needs to consume info->pol[] in
the same forward order as the rule layout.

Derive the strict-match policy position from the number of transforms
already consumed so that multi-element inbound rules are matched
consistently.

Weakness: CWE-682 (Incorrect Calculation)

## Which versions are affected by CVE-2026-52920?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52920?

Apply the vendor's patch.

## Is CVE-2026-52920 being exploited?

There is no known exploitation of CVE-2026-52920 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-2026-52920 and fix it if it is affected.

What it is: CVE-2026-52920 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-52920 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-2026-52920/ (Markdown: https://insights.sbomify.com/CVE-2026-52920/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52920
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52920
- OSV: https://osv.dev/vulnerability/CVE-2026-52920

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52920/
Summaries are generated and may contain mistakes; the official description above is the record.