# CVE-2026-3679: Tenda FH451 QuickIndex formQuickIndex stack-based overflow

> A remote attacker can execute arbitrary code on Tenda FH451 routers via a stack-based buffer overflow in the QuickIndex form.

- **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:** 7 Mar 2026
- **Updated:** 11 Mar 2026
- **Also known as:** GHSA-f282-6248-c3xx

## What is CVE-2026-3679?

CVE-2026-3679 is a high-severity memory corruption vulnerability in Tenda FH451, published on 7 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was identified in Tenda FH451 1.0.0.9. Affected by this vulnerability is the function formQuickIndex of the file /goform/QuickIndex. Such manipulation of the argument mit_linktype/PPPOEPassword leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit is publicly available and might 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-2026-3679?

It affects 1 product.


Products: Tenda F451 Firmware.

## How do I fix CVE-2026-3679?

No fix has been published for CVE-2026-3679 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3679 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3679 exists.

## Other vulnerabilities in Tenda FH451

- [CVE-2026-6120](https://insights.sbomify.com/CVE-2026-6120/): Tenda F451 httpd DhcpListClient fromDhcpListClient stack-based overflow (high 8.7)
- [CVE-2026-6121](https://insights.sbomify.com/CVE-2026-6121/): Tenda F451 httpd WrlclientSet stack-based overflow (high 8.7)
- [CVE-2026-6122](https://insights.sbomify.com/CVE-2026-6122/): Tenda F451 httpd L7Prot frmL7ProtForm stack-based overflow (high 8.7)
- [CVE-2026-6123](https://insights.sbomify.com/CVE-2026-6123/): Tenda F451 httpd addressNat fromAddressNat stack-based overflow (high 8.7)
- [CVE-2026-6124](https://insights.sbomify.com/CVE-2026-6124/): Tenda F451 httpd SafeMacFilter fromSafeMacFilter stack-based overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3679 and fix it if it is affected.

What it is: CVE-2026-3679 is a high-severity memory corruption vulnerability in Tenda FH451, published on 7 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-2026-3679 exists.

Affected product: Tenda FH451. 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-2026-3679/ (Markdown: https://insights.sbomify.com/CVE-2026-3679/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3679
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3679
- OSV: https://osv.dev/vulnerability/CVE-2026-3679

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-3679/
Summaries are generated and may contain mistakes; the official description above is the record.