# CVE-2026-5684: Tenda CX12L webExcptypemanFilter fromwebExcptypemanFilter stack-based overflow

> A stack-based buffer overflow in the Tenda CX12L router allows local network attackers to execute arbitrary code or cause denial of service.

- **Severity:** High 8.6 (`CVSS:4.0/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Apr 2026
- **Updated:** 7 Apr 2026
- **Also known as:** GHSA-phcm-xmm8-7jpc

## What is CVE-2026-5684?

CVE-2026-5684 is a high-severity memory corruption vulnerability in Tenda CX12L, published on 6 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was determined in Tenda CX12L 16.03.53.12. Affected by this issue is the function fromwebExcptypemanFilter of the file /goform/webExcptypemanFilter. Executing a manipulation of the argument page can lead to stack-based buffer overflow. The attack requires access to the local network. The exploit has been publicly disclosed and may be utilized.

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

## Which versions are affected by CVE-2026-5684?

It affects 1 product.


Products: Tenda Cx12l Firmware.

## How do I fix CVE-2026-5684?

No fix has been published for CVE-2026-5684 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5684 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5684 exists.

## Other vulnerabilities in Tenda CX12L

- [CVE-2026-8138](https://insights.sbomify.com/CVE-2026-8138/): Tenda CX12L SetPptpServerCfg” formSetPPTPServer stack-based overflow (high 8.7)
- [CVE-2026-5685](https://insights.sbomify.com/CVE-2026-5685/): Tenda CX12L addressNat fromAddressNat stack-based overflow (high 8.7)
- [CVE-2026-5686](https://insights.sbomify.com/CVE-2026-5686/): Tenda CX12L RouteStatic fromRouteStatic stack-based overflow (high 8.7)
- [CVE-2026-5687](https://insights.sbomify.com/CVE-2026-5687/): Tenda CX12L NatStaticSetting fromNatStaticSetting stack-based overflow (high 8.7)
- [CVE-2026-5683](https://insights.sbomify.com/CVE-2026-5683/): Tenda CX12L P2pListFilter fromP2pListFilter stack-based overflow (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5684 and fix it if it is affected.

What it is: CVE-2026-5684 is a high-severity memory corruption vulnerability in Tenda CX12L, published on 6 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5684 exists.

Affected product: Tenda CX12L. 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-2026-5684/ (Markdown: https://insights.sbomify.com/CVE-2026-5684/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5684
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5684
- OSV: https://osv.dev/vulnerability/CVE-2026-5684

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5684/
Summaries are generated and may contain mistakes; the official description above is the record.