# CVE-2026-53238: netlabel: validate unlabeled address and mask attribute lengths

> A crafted Generic Netlink request in the Linux kernel could trigger an out-of-bounds read, potentially disclosing sensitive memory contents.

- **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:** 25 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** AZL-90873, BELL-CVE-2026-53238, DEBIAN-CVE-2026-53238, GHSA-5qwx-4q7j-hwm2, ROOT-OS-DEBIAN-11-CVE-2026-53238, ROOT-OS-DEBIAN-12-CVE-2026-53238, ROOT-OS-UBUNTU-2204-CVE-2026-53238, ROOT-OS-UBUNTU-2404-CVE-2026-53238, UBUNTU-CVE-2026-53238

## What is CVE-2026-53238?

CVE-2026-53238 is a medium-severity vulnerability in Linux kernel, published on 25 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:

netlabel: validate unlabeled address and mask attribute lengths

netlbl_unlabel_addrinfo_get() used the address attribute length to
determine whether the attribute data could be read as an IPv4 or IPv6
address, but did not independently validate the corresponding mask
attribute length.  A crafted Generic Netlink request could therefore
provide a valid IPv4/IPv6 address attribute with a shorter mask
attribute, which would later be read as a full struct in_addr or
struct in6_addr.

NLA_BINARY policy lengths are maximum lengths by default, so use
NLA_POLICY_EXACT_LEN() for the unlabeled IPv4/IPv6 address and mask
attributes.  This rejects short attributes during policy validation and
also exposes the exact length requirements through policy introspection.

## Which versions are affected by CVE-2026-53238?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53238?

Apply the vendor's patch.

## Is CVE-2026-53238 being exploited?

There is no known exploitation of CVE-2026-53238 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-2026-53238 and fix it if it is affected.

What it is: CVE-2026-53238 is a medium-severity vulnerability in Linux kernel, published on 25 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-2026-53238 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-2026-53238/ (Markdown: https://insights.sbomify.com/CVE-2026-53238/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53238
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53238
- OSV: https://osv.dev/vulnerability/CVE-2026-53238

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53238/
Summaries are generated and may contain mistakes; the official description above is the record.