# CVE-2026-3975: Tenda W3 POST Parameter WifiMacFilterGet formWifiMacFilterGet stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the Tenda W3 router via the WifiMacFilterGet POST parameter, potentially leading to code execution.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Mar 2026
- **Updated:** 12 Mar 2026
- **Also known as:** GHSA-r9cv-9j6h-2cv2

## What is CVE-2026-3975?

CVE-2026-3975 is a high-severity memory corruption vulnerability in Tenda W3, published on 12 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A security flaw has been discovered in Tenda W3 1.0.0.3(2204). This issue affects the function formWifiMacFilterGet of the file /goform/WifiMacFilterGet of the component POST Parameter Handler. Performing a manipulation of the argument wl_radio results in stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-787 (Out-of-bounds Write), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-3975?

It affects 1 product.


Products: Tenda W3 Firmware.

## How do I fix CVE-2026-3975?

No fix has been published for CVE-2026-3975 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3975 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3975 exists.

## Other vulnerabilities in Tenda W3

- [CVE-2026-3972](https://insights.sbomify.com/CVE-2026-3972/): Tenda W3 HTTP setcfm formSetCfm stack-based overflow (high 8.7)
- [CVE-2026-3973](https://insights.sbomify.com/CVE-2026-3973/): Tenda W3 POST Parameter setAutoPing formSetAutoPing stack-based overflow (high 8.7)
- [CVE-2026-3974](https://insights.sbomify.com/CVE-2026-3974/): Tenda W3 HTTP exeCommand formexeCommand stack-based overflow (high 8.7)
- [CVE-2026-3976](https://insights.sbomify.com/CVE-2026-3976/): Tenda W3 POST Parameter WifiMacFilterSet formWifiMacFilterSet stack-based overflow (high 8.7)
- [CVE-2026-4007](https://insights.sbomify.com/CVE-2026-4007/): Tenda W3 POST Parameter wifiSSIDget stack-based overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3975 and fix it if it is affected.

What it is: CVE-2026-3975 is a high-severity memory corruption vulnerability in Tenda W3, published on 12 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3975 exists.

Affected product: Tenda W3. 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-2026-3975/ (Markdown: https://insights.sbomify.com/CVE-2026-3975/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3975
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3975
- OSV: https://osv.dev/vulnerability/CVE-2026-3975

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3975/
Summaries are generated and may contain mistakes; the official description above is the record.