# CVE-2026-23408: apparmor: Fix double free of ns_name in aa_replace_profiles()

> A double free vulnerability in the Linux kernel's AppArmor module allows attackers to potentially execute arbitrary code or escalate privileges.

- **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:** 1 Apr 2026
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-82028, BELL-CVE-2026-23408, DEBIAN-CVE-2026-23408, GHSA-qcx9-4fj7-jf29, UBUNTU-CVE-2026-23408

## What is CVE-2026-23408?

CVE-2026-23408 is a high-severity use after free vulnerability in Linux kernel, published on 1 Apr 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:

apparmor: Fix double free of ns_name in aa_replace_profiles()

if ns_name is NULL after
1071         error = aa_unpack(udata, &lh, &ns_name);

and if ent->ns_name contains an ns_name in
1089                 } else if (ent->ns_name) {

then ns_name is assigned the ent->ns_name
1095                         ns_name = ent->ns_name;

however ent->ns_name is freed at
1262                 aa_load_ent_free(ent);

and then again when freeing ns_name at
1270         kfree(ns_name);

Fix this by NULLing out ent->ns_name after it is transferred to ns_name

")

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2026-23408?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23408?

Apply the vendor's patch.

## Is CVE-2026-23408 being exploited?

There is no known exploitation of CVE-2026-23408 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-2026-23408 and fix it if it is affected.

What it is: CVE-2026-23408 is a high-severity use after free vulnerability in Linux kernel, published on 1 Apr 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-2026-23408 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-2026-23408/ (Markdown: https://insights.sbomify.com/CVE-2026-23408/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23408
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23408
- OSV: https://osv.dev/vulnerability/CVE-2026-23408

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23408/
Summaries are generated and may contain mistakes; the official description above is the record.