# CVE-2025-39891: wifi: mwifiex: Initialize the chan_stats array to zero

> A local attacker can read uninitialized kernel memory via the mwifiex Wi-Fi driver, potentially exposing sensitive data.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 1 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-68007, AZL-75122, BELL-CVE-2025-39891, DEBIAN-CVE-2025-39891, GHSA-2237-jrrh-3624, ROOT-OS-DEBIAN-11-CVE-2025-39891, ROOT-OS-UBUNTU-2204-CVE-2025-39891, ROOT-OS-UBUNTU-2404-CVE-2025-39891, UBUNTU-CVE-2025-39891

## What is CVE-2025-39891?

CVE-2025-39891 is a high-severity vulnerability in Debian Debian Linux, published on 1 Oct 2025. 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: mwifiex: Initialize the chan_stats array to zero

The adapter->chan_stats[] array is initialized in
mwifiex_init_channel_scan_gap() with vmalloc(), which doesn't zero out
memory.  The array is filled in mwifiex_update_chan_statistics()
and then the user can query the data in mwifiex_cfg80211_dump_survey().

There are two potential issues here.  What if the user calls
mwifiex_cfg80211_dump_survey() before the data has been filled in.
Also the mwifiex_update_chan_statistics() function doesn't necessarily
initialize the whole array.  Since the array was not initialized at
the start that could result in an information leak.

Also this array is pretty small.  It's a maximum of 900 bytes so it's
more appropriate to use kcalloc() instead vmalloc().

## Which versions are affected by CVE-2025-39891?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-39891?

Apply the vendor's patch.

## Is CVE-2025-39891 being exploited?

There is no known exploitation of CVE-2025-39891 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-39891 and fix it if it is affected.

What it is: CVE-2025-39891 is a high-severity vulnerability in Debian Debian Linux, published on 1 Oct 2025. 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-2025-39891 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2025-39891/ (Markdown: https://insights.sbomify.com/CVE-2025-39891/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39891
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39891
- OSV: https://osv.dev/vulnerability/CVE-2025-39891

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39891/
Summaries are generated and may contain mistakes; the official description above is the record.