# CVE-2026-104611: Tenda AC9 POST Request fast_setting_internet_set stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the Tenda AC9 router via a crafted POST request, potentially leading to code execution.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2026
- **Updated:** 2 Oct 2026
- **Also known as:** GHSA-5xvg-86hf-5h5q

## What is CVE-2026-104611?

CVE-2026-104611 is a critical memory corruption vulnerability in Tenda AC9, published on 2 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability was detected in Tenda AC9 15.03.02.13. Affected is an unknown function of the file /goform/fast_setting_internet_set of the component POST Request Handler. Performing a manipulation of the argument netWanType results in stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit is now public 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-2026-104611?


## How do I fix CVE-2026-104611?

No fix has been published for CVE-2026-104611 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104611 being exploited?

There is no known exploitation of CVE-2026-104611 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104611 and fix it if it is affected.

What it is: CVE-2026-104611 is a critical memory corruption vulnerability in Tenda AC9, published on 2 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-104611 in the wild and no public exploit code.

Affected product: Tenda AC9. 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-2026-104611/ (Markdown: https://insights.sbomify.com/CVE-2026-104611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104611
- OSV: https://osv.dev/vulnerability/CVE-2026-104611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104611/
Summaries are generated and may contain mistakes; the official description above is the record.