RIOT OS Users Face Critical RCE Risk from Nearby Attackers via ATWINC15x0 Driver Buffer Overflow

A buffer overflow in the ATWINC15x0 Wi-Fi driver of the RIOT operating system allows attackers to execute arbitrary code on embedded devices. The flaw, tracked as CVE-2026-102693, occurs when the system processes network names without verifying their length. According to the National Vulnerability Database, this issue affects all RIOT OS releases before version 2026.04.

How does the vulnerability work?

The root cause lies in the _atwinc15x0_sta_set_current_ssid function within the ATWINC15x0 driver. This function uses the strcpy command to copy a Service Set Identifier into a memory buffer. The National Vulnerability Database records that the code fails to check the size of the destination buffer before performing this copy. This lack of boundary checking creates a classic buffer overflow condition.

What is required for exploitation?

An attacker must be physically near the target device to exploit this flaw. The National Vulnerability Database states that the attacker advertises a malformed or oversized SSID. The target device processes this name during its standard Wi-Fi scanning routine. This interaction only triggers the vulnerability if the MODULE_ATWINC15X0_DYNAMIC_CONNECT module is enabled in the RIOT OS configuration.

What are the potential impacts?

Processing the oversized SSID causes memory corruption within the embedded system. The National Vulnerability Database lists several possible outcomes of this corruption. These include a hard fault that crashes the device, a denial of service that renders it unusable, or the execution of arbitrary code by the attacker. The CVSS score of 9.6 reflects the severity of these potential outcomes.

Is a fix available?

Yes, the RIOT OS project has addressed this issue. The National Vulnerability Database confirms that the vulnerability is fixed in version 2026.04. Organizations using earlier versions of the open-source microcontroller operating system should update to this release or later. This update patches the unsafe string copying behavior in the Wi-Fi driver.

What analysts watch for

Security teams should monitor embedded device logs for unexpected Wi-Fi scanning activity or connection attempts to non-existent networks. Analysts typically look for signs of memory corruption, such as application crashes or hard faults, coinciding with wireless interface events. When investigating potential compromises, examine the firmware for unauthorized modifications or new processes running on the microcontroller. Check whether the dynamic connect module was active during the incident window, as this is a prerequisite for this specific attack vector.

Background: National Vulnerability Database

The National Vulnerability Database lists known flaws but lacks deployment context. Do not treat every entry as an immediate emergency. Cross-reference findings with your asset inventory and usage patterns to determine real risk, rather than reacting to every new identifier.

Read the full guide: National Vulnerability Database: Five Common Misreadings and Fixes

What to do and how to stay safe: RIOT OS

• Update all RIOT OS-based devices to version 2026.04 or later to patch the buffer overflow.
• Audit device configurations to disable MODULE_ATWINC15X0_DYNAMIC_CONNECT if the feature is not required.
• Monitor network logs for SSIDs with unusually long or malformed characters that do not match known networks.
• Review embedded system crash logs for patterns indicating memory corruption during Wi-Fi scanning operations.

Step-by-step guide: How Vulnerability Scanning Works: The Hidden Mechanics and Limits

General security guidance from the Sandbox Desk newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

Which CVE ID tracks this RIOT OS vulnerability?

The vulnerability is tracked as CVE-2026-102693.

What CVSS score does the NVD assign to this flaw?

The National Vulnerability Database assigns a CVSS score of 9.6, rating it as Critical.

Which RIOT OS versions are affected by this issue?

All versions of RIOT OS prior to 2026.04 are affected by this buffer overflow.