# CVE-2026-28520: arduino-TuyaOpen WiFiMulti Single-Byte Buffer Overflow Remote Code Execution

> Attacker executes arbitrary code on Tuya smart devices by exploiting a buffer overflow in the WiFiMulti component during AP connection.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Mar 2026
- **Updated:** 16 Mar 2026
- **Also known as:** GHSA-3w55-cqrx-x67w

## What is CVE-2026-28520?

CVE-2026-28520 is a high-severity memory corruption vulnerability in arduino-TuyaOpen, published on 15 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

arduino-TuyaOpen before version 1.2.1 contains a single-byte buffer overflow vulnerability in the WiFiMulti component. When the victim's smart hardware connects to an attacker-controlled AP hotspot, the attacker can exploit the overflow to execute arbitrary code on the affected embedded device.

Weakness: CWE-193 (Off-by-one Error)

## Which versions are affected by CVE-2026-28520?

It affects 1 product.


Products: Tuya Arduino-Tuyaopen.

## How do I fix CVE-2026-28520?

No fix has been published for CVE-2026-28520 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-28520 being exploited?

There is no known exploitation of CVE-2026-28520 in the wild and no public exploit code.

## Other vulnerabilities in arduino-TuyaOpen

- [CVE-2026-28519](https://insights.sbomify.com/CVE-2026-28519/): arduino-TuyaOpen DnsServer Heap-Based Buffer Overflow Remote Code Execution (high 8.7)
- [CVE-2026-28522](https://insights.sbomify.com/CVE-2026-28522/): arduino-TuyaOpen WiFiUDP Null Pointer Dereference Denial of Service (high 7.1)
- [CVE-2026-28521](https://insights.sbomify.com/CVE-2026-28521/): arduino-TuyaOpen TuyaIoT Out-of-Bounds Memory Read Information Disclosure (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28520 and fix it if it is affected.

What it is: CVE-2026-28520 is a high-severity memory corruption vulnerability in arduino-TuyaOpen, published on 15 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-28520 in the wild and no public exploit code.

Affected product: arduino-TuyaOpen. 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-2026-28520/ (Markdown: https://insights.sbomify.com/CVE-2026-28520/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28520
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28520
- OSV: https://osv.dev/vulnerability/CVE-2026-28520

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28520/
Summaries are generated and may contain mistakes; the official description above is the record.