# CVE-2026-4906: Tenda AC5 POST Request WizardHandle decodePwd stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the Tenda AC5 router's password decoding function, 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:** 27 Mar 2026
- **Updated:** 30 Mar 2026
- **Also known as:** GHSA-cfmp-f27r-2qg4

## What is CVE-2026-4906?

CVE-2026-4906 is a high-severity memory corruption vulnerability in Tenda AC5, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was determined in Tenda AC5 15.03.06.47. The affected element is the function decodePwd of the file /goform/WizardHandle of the component POST Request Handler. Executing a manipulation of the argument WANT/WANS can lead to stack-based buffer overflow. The attack can be executed remotely. The exploit has been publicly disclosed and may be utilized.

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-2026-4906?

It affects 1 product.


Products: Tenda Ac5 Firmware.

## How do I fix CVE-2026-4906?

No fix has been published for CVE-2026-4906 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4906 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4906 exists.

## Other vulnerabilities in Tenda AC5

- [CVE-2023-41553](https://insights.sbomify.com/CVE-2023-41553/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-41556](https://insights.sbomify.com/CVE-2023-41556/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-41557](https://insights.sbomify.com/CVE-2023-41557/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-41559](https://insights.sbomify.com/CVE-2023-41559/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-41561](https://insights.sbomify.com/CVE-2023-41561/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4906 and fix it if it is affected.

What it is: CVE-2026-4906 is a high-severity memory corruption vulnerability in Tenda AC5, published on 27 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-2026-4906 exists.

Affected product: Tenda AC5. 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-2026-4906/ (Markdown: https://insights.sbomify.com/CVE-2026-4906/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4906
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4906
- OSV: https://osv.dev/vulnerability/CVE-2026-4906

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4906/
Summaries are generated and may contain mistakes; the official description above is the record.