CVE-2026-22213 is a stack-based buffer overflow vulnerability identified in the tapslip6 utility of RIOT OS, an operating system designed for Internet of Things (IoT) devices. The vulnerability stems from the devopen() function, which constructs a device path by concatenating a fixed prefix '/dev/' with a user-supplied device name provided through the -s command-line option. This concatenation is performed using unsafe functions strcpy() and strcat() without any bounds checking, allowing an attacker to supply an excessively long device name string. This leads to a stack buffer overflow, which can cause process crashes and memory corruption. The vulnerability requires the attacker to have local privileges to execute the tapslip6 utility and to provide crafted input, implying user interaction is necessary. The CVSS 4.0 vector indicates low attack vector (local), low complexity, no privileges required beyond local, user interaction needed, and low impact on confidentiality, integrity, and availability. No patches or exploits are currently known, but the issue is publicly disclosed and should be addressed in future RIOT OS releases.

For European organizations, the impact of this vulnerability is generally low due to the limited scope and conditions required for exploitation. RIOT OS is primarily used in IoT and embedded systems, often in constrained environments. A successful exploit could cause denial of service through process crashes or potentially memory corruption, which might be leveraged for further attacks if combined with other vulnerabilities. However, the need for local access and user interaction reduces the risk of remote exploitation. Organizations deploying RIOT OS in critical infrastructure or industrial IoT devices should consider the potential for disruption or device malfunction. The vulnerability does not directly compromise confidentiality or integrity but could affect availability of affected components. Given the low CVSS score and no known exploits, the immediate threat level is low but should not be ignored in security assessments of IoT deployments.

To mitigate this vulnerability, organizations should monitor for updates from the RIOT OS project and apply patches once available. In the interim, restrict access to devices running RIOT OS and limit user permissions to prevent unauthorized execution of the tapslip6 utility. Implement strict input validation or sanitization on any user-supplied device names if custom modifications are possible. Employ runtime protections such as stack canaries or address space layout randomization (ASLR) where supported by the platform to reduce exploitation risk. Conduct regular security audits of IoT devices and isolate them within segmented network zones to minimize impact if exploitation occurs. Additionally, educate users and administrators about the risks of executing untrusted commands or utilities locally on IoT devices.