# CVE-2025-21439: Out-of-bounds Read in Windows WLAN Host

> Out-of-bounds read in Qualcomm Snapdragon WLAN driver allows memory corruption and potential code execution via IOCTL calls.

- **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:** No
- **Published:** 7 Apr 2025
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-4fr5-x8r3-mvxg

## What is CVE-2025-21439?

CVE-2025-21439 is a high-severity memory corruption vulnerability in Qualcomm Fastconnect 6700 Firmware, published on 7 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Memory corruption may occur while reading board data via IOCTL call when the WLAN driver copies the content to the provided output buffer.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-21439?

It affects 25 products.


Products: Qualcomm Fastconnect 6700 Firmware, Qualcomm Fastconnect 6900 Firmware, Qualcomm Qca6595au Firmware, Qualcomm Qcm5430 Firmware, Qualcomm Qcm6490 Firmware, Qualcomm Qcn7605 Firmware, Qualcomm Qcn7606 Firmware, Qualcomm Qcs5430 Firmware, Qualcomm Qcs6490 Firmware, Qualcomm Sc8180x\+sdx55 Firmware, Qualcomm Snapdragon 8c Compute Platform \(Sc8180x-Ad\) Firmware, Qualcomm Snapdragon 8c Compute Platform \(Sc8180xp-Ad\) Firmware, Qualcomm Snapdragon 8cx Compute Platform \(Sc8180x-Aa\) Firmware, Qualcomm Snapdragon 8cx Compute Platform \(Sc8180x-Ab\) Firmware, Qualcomm Snapdragon 8cx Compute Platform \(Sc8180xp-Ac\) Firmware, Qualcomm Snapdragon 8cx Compute Platform \(Sc8180xp-Af\) Firmware, Qualcomm Snapdragon 8cx Gen 2 5g Compute Platform \(Sc8180x-Ac\) Firmware, Qualcomm Snapdragon 8cx Gen 2 5g Compute Platform \(Sc8180x-Af\) Firmware, Qualcomm Snapdragon 8cx Gen 2 5g Compute Platform \(Sc8180xp-Aa\) Firmware, Qualcomm Snapdragon 8cx Gen 2 5g Compute Platform \(Sc8180xp-Ab\) Firmware and 5 more.

## How do I fix CVE-2025-21439?

No fix has been published for CVE-2025-21439 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-21439 being exploited?

There is no known exploitation of CVE-2025-21439 in the wild and no public exploit code.

## Other vulnerabilities in Qualcomm Fastconnect 6700 Firmware

- [CVE-2024-43047](https://insights.sbomify.com/CVE-2024-43047/): Qualcomm Multiple Chipsets Use-After-Free (high 7.8, exploited in the wild)
- [CVE-2023-21671](https://insights.sbomify.com/CVE-2023-21671/): Improper Input Validation in Core (critical 9.3)
- [CVE-2024-21464](https://insights.sbomify.com/CVE-2024-21464/): Buffer Copy Without Checking Size of Input in Data Network Stack & Connectivity (high 8.4)
- [CVE-2024-33047](https://insights.sbomify.com/CVE-2024-33047/): Buffer Over-read in Display (high 8.4)
- [CVE-2024-23360](https://insights.sbomify.com/CVE-2024-23360/): Improper Access Control in Graphics Windows (high 8.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21439 and fix it if it is affected.

What it is: CVE-2025-21439 is a high-severity memory corruption vulnerability in Qualcomm Fastconnect 6700 Firmware, published on 7 Apr 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-2025-21439 in the wild and no public exploit code.

Affected product: Qualcomm Fastconnect 6700 Firmware. 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-2025-21439/ (Markdown: https://insights.sbomify.com/CVE-2025-21439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21439
- OSV: https://osv.dev/vulnerability/CVE-2025-21439

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21439/
Summaries are generated and may contain mistakes; the official description above is the record.