# CVE-2026-23281: wifi: libertas: fix use-after-free in lbs_free_adapter()

> A use-after-free vulnerability in the Linux kernel libertas Wi-Fi driver allows attackers to cause denial of service or execute arbitrary code via timer race conditions.

- **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:** 25 Mar 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-80700, BELL-CVE-2026-23281, DEBIAN-CVE-2026-23281, GHSA-f429-w42v-q89c, ROOT-OS-DEBIAN-11-CVE-2026-23281, ROOT-OS-DEBIAN-12-CVE-2026-23281, ROOT-OS-DEBIAN-13-CVE-2026-23281, ROOT-OS-UBUNTU-2204-CVE-2026-23281, ROOT-OS-UBUNTU-2404-CVE-2026-23281, UBUNTU-CVE-2026-23281

## What is CVE-2026-23281?

CVE-2026-23281 is a high-severity use after free vulnerability in Linux kernel, published on 25 Mar 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:

wifi: libertas: fix use-after-free in lbs_free_adapter()

The lbs_free_adapter() function uses timer_delete() (non-synchronous)
for both command_timer and tx_lockup_timer before the structure is
freed. This is incorrect because timer_delete() does not wait for
any running timer callback to complete.

If a timer callback is executing when lbs_free_adapter() is called,
the callback will access freed memory since lbs_cfg_free() frees the
containing structure immediately after lbs_free_adapter() returns.

Both timer callbacks (lbs_cmd_timeout_handler and lbs_tx_lockup_handler)
access priv->driver_lock, priv->cur_cmd, priv->dev, and other fields,
which would all be use-after-free violations.

Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning.

This bug was introduced in commit 8f641d93c38a ("libertas: detect TX
lockups and reset hardware") where del_timer() was used instead of
del_timer_sync() in the cleanup path. The command_timer has had the
same issue since the driver was first written.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-23281?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23281?

Apply the vendor's patch.

## Is CVE-2026-23281 being exploited?

There is no known exploitation of CVE-2026-23281 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-2026-23281 and fix it if it is affected.

What it is: CVE-2026-23281 is a high-severity use after free vulnerability in Linux kernel, published on 25 Mar 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-2026-23281 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-2026-23281/ (Markdown: https://insights.sbomify.com/CVE-2026-23281/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23281
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23281
- OSV: https://osv.dev/vulnerability/CVE-2026-23281

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23281/
Summaries are generated and may contain mistakes; the official description above is the record.