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Arduino TuyaopenApplication · Tuya

CVE-2026-28519

HIGH · 8.8 CVSS v3.1 Published 2026-03-16
Fix available
A fix is available. Upgrade to 1.2.1 or later.
See remediation →
93/100
Remediation priority · Urgent
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
arduino-TuyaOpen before version 1.2.1 contains a heap-based buffer overflow vulnerability in the DnsServer component. An attacker on the same local area network who controls the LAN DNS server can send malicious DNS responses to overflow the heap buffer, potentially allowing execution of arbitrary code on affected embedded devices.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The arduino-TuyaOpen library before version 1.2.1 contains a heap-based buffer overflow vulnerability in its DnsServer component. An attacker who controls the LAN DNS server on the same local network can send specially crafted malicious DNS responses that overflow the heap buffer allocated for DNS processing, potentially leading to arbitrary code execution on affected IoT/embedded devices using this library.

MitigationUpgrade arduino-TuyaOpen to version 1.2.1 or later to obtain the patch. Additionally, implement network segmentation and restrict untrusted devices from controlling the LAN DNS server to reduce the attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Arduino TuyaopenApplication
Affected:< 1.2.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify arduino-TuyaOpen library usage
    Search project source files for #include statements referencing TuyaOpen or DNS server headers (e.g., #include <DnsServer.h>, #include <TuyaOpen.h>) or examine the project's library dependencies configuration
    Affected if The library is present in the project dependencies or included in source files
  2. Determine installed library version
    Check the library.properties file or platformio.ini/lib folder for the arduino-TuyaOpen version number, or run library manager query for installed version
    Affected if The installed version is below 1.2.1 (e.g., 1.2.0, 1.1.x, or any version < 1.2.1)
  3. Verify DnsServer component is active
    Search source code for DnsServer class instantiation (e.g., 'DnsServer dnsServer;' or 'dnsServer.start(...)') and verify the DNS server is actually initialized and running on the device
    Affected if DnsServer is instantiated and started in the firmware code, meaning the device is actually processing DNS requests
  4. Check network exposure
    Review network configuration to determine if the device is on a shared local network where untrusted LAN DNS servers could be controlled by an attacker
    Affected if The device resides on a network where an attacker could position themselves as the LAN DNS server

A device is affected if it uses the arduino-TuyaOpen library version below 1.2.1 AND has the DnsServer component enabled and operational, particularly on a network where an attacker could control the LAN DNS server.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.2.1 or later
Fixed in 1.2.1
Interim mitigation

Upgrade arduino-TuyaOpen to version 1.2.1 or later to obtain the patch. Additionally, implement network segmentation and restrict untrusted devices from controlling the LAN DNS server to reduce the attack surface.

Recommended fix High confidence

arduino-TuyaOpen version 1.2.1

  1. 1. Identify all instances of arduino-TuyaOpen library in your project dependencies (e.g., in platformio.ini, Arduino library.json, or IDE library manager)
  2. 2. Locate the current version of arduino-TuyaOpen being used
  3. 3. Update the library dependency to version 1.2.1 or later
  4. 4. Rebuild the project to ensure compatibility with the new library version
  5. 5. Redeploy the updated firmware to all affected embedded devices
  6. 6. Verify the DnsServer component functions correctly after the upgrade
Caveat Minor version upgrades may include API changes; review any DnsServer-related code for compatibility issues before deploying to production

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Arduino Tuyaopen Scoped from the published advisory
  • Consultation6.0 h
  • Implementation10.0 h
  • Testing6.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,620
Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-28519 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data