# CVE-2026-28521: arduino-TuyaOpen TuyaIoT Out-of-Bounds Memory Read Information Disclosure

> Attacker controlling Tuya cloud can send malicious data to devices, causing out-of-bounds reads that leak information or crash the device.

- **Severity:** High 7.0 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/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-r4wm-392x-hfg5

## What is CVE-2026-28521?

CVE-2026-28521 is a high-severity 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 an out-of-bounds memory read vulnerability in the TuyaIoT component. An attacker who hijacks or controls the Tuya cloud service can issue malicious DP event data to victim devices, causing out-of-bounds memory access that may result in information disclosure or a denial-of-service condition.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-28521?

It affects 1 product.


Products: Tuya Arduino-Tuyaopen.

## How do I fix CVE-2026-28521?

No fix has been published for CVE-2026-28521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-28521 being exploited?

There is no known exploitation of CVE-2026-28521 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-2026-28520](https://insights.sbomify.com/CVE-2026-28520/): arduino-TuyaOpen WiFiMulti Single-Byte Buffer Overflow Remote Code Execution (high 8.6)
- [CVE-2026-28522](https://insights.sbomify.com/CVE-2026-28522/): arduino-TuyaOpen WiFiUDP Null Pointer Dereference Denial of Service (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28521 and fix it if it is affected.

What it is: CVE-2026-28521 is a high-severity 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-2026-28521 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-2026-28521/ (Markdown: https://insights.sbomify.com/CVE-2026-28521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28521
- OSV: https://osv.dev/vulnerability/CVE-2026-28521

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-28521/
Summaries are generated and may contain mistakes; the official description above is the record.