# CVE-2026-5609: Tenda i12 Parameter wifiSSIDset formwrlSSIDset stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the Tenda i12 router's Wi-Fi SSID parameter handler, potentially leading to code execution or service disruption.

- **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:** 6 Apr 2026
- **Updated:** 6 Apr 2026
- **Also known as:** GHSA-26hh-9qh7-grjv

## What is CVE-2026-5609?

CVE-2026-5609 is a high-severity memory corruption vulnerability in Tenda i12, published on 6 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw has been found in Tenda i12 1.0.0.11(3862). Affected by this vulnerability is the function formwrlSSIDset of the file /goform/wifiSSIDset of the component Parameter Handler. This manipulation of the argument index/wl_radio causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been published and may be used.

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-2026-5609?

It affects 1 product.


Products: Tenda I12 Firmware.

## How do I fix CVE-2026-5609?

No fix has been published for CVE-2026-5609 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5609 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5609 exists.

## Other vulnerabilities in Tenda i12

- [CVE-2025-25676](https://insights.sbomify.com/CVE-2025-25676/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-25678](https://insights.sbomify.com/CVE-2025-25678/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-4041](https://insights.sbomify.com/CVE-2026-4041/): Tenda i12 exeCommand vos_strcpy stack-based overflow (high 8.7)
- [CVE-2026-4042](https://insights.sbomify.com/CVE-2026-4042/): Tenda i12 WifiMacFilterGet formWifiMacFilterGet stack-based overflow (high 8.7)
- [CVE-2026-4043](https://insights.sbomify.com/CVE-2026-4043/): Tenda i12 wifiSSIDget formwrlSSIDget stack-based overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5609 and fix it if it is affected.

What it is: CVE-2026-5609 is a high-severity memory corruption vulnerability in Tenda i12, published on 6 Apr 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-2026-5609 exists.

Affected product: Tenda i12. 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-2026-5609/ (Markdown: https://insights.sbomify.com/CVE-2026-5609/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5609
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5609
- OSV: https://osv.dev/vulnerability/CVE-2026-5609

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5609/
Summaries are generated and may contain mistakes; the official description above is the record.