CVE-2026-28520

Code execution via undersized WiFiMulti string allocations

Published Mar 15, 2026 · Updated Mar 15, 2026

Off-by-one buffer overflow in Tuya arduino-tuyaopen before 1.2.1 allows physically proximate attackers to execute code via a Wi-Fi AP. WiFiMulti::addAP allocates exactly strlen(ssid) or strlen(passphrase) bytes and then uses strcpy, so the terminating null byte is written past either heap buffer. Exploitation requires the embedded device to connect to an attacker-controlled hotspot; successful corruption grants code execution on that device.

CVSS severity8.6
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Off-by-one buffer overflow in Tuya arduino-tuyaopen before 1.2.1 allows physically proximate attackers to execute code via a Wi-Fi AP. WiFiMulti::addAP allocates exactly strlen(ssid) or strlen(passphrase) bytes and then uses strcpy, so the terminating null byte is written past either heap buffer. Exploitation requires the embedded device to connect to an attacker-controlled hotspot; successful corruption grants code execution on that device.

The record

CVE
CVE-2026-28520
Published
Mar 15, 2026
Updated
Mar 15, 2026
Vendor
Tuya
Product
arduino-tuyaopen
Classifications
CWE-193
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.2.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Tuya · arduino-tuyaopenversion=0 <1.2.1

Published CVSS scores

8.6VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.4VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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