CVE-2025-50262 is a buffer overflow vulnerability identified in the Tenda AC6 router firmware version v15.03.05.16_multi. The vulnerability exists in the formSetQosBand function, specifically triggered via the 'list' parameter. Buffer overflow vulnerabilities occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory. This can lead to arbitrary code execution, denial of service, or system crashes. In this case, exploitation of the vulnerability could allow an attacker to execute arbitrary code with the privileges of the affected process, which is likely running with elevated permissions on the router. The vulnerability is in the QoS (Quality of Service) configuration component, which is typically accessible via the router's management interface or potentially via network requests. No CVSS score has been assigned yet, and there are no known exploits in the wild at the time of publication. The affected version is specifically the Tenda AC6 firmware v15.03.05.16_multi, with no other versions explicitly listed. No patches or mitigations have been published yet. The vulnerability was reserved on June 16, 2025, and published on July 3, 2025. Given the nature of buffer overflow vulnerabilities in network devices, this issue could be exploited remotely if the vulnerable function is exposed to network inputs, potentially allowing attackers to compromise the router, intercept or manipulate network traffic, or pivot into internal networks.

For European organizations, the impact of this vulnerability could be significant, especially for small and medium enterprises (SMEs) and home office environments that commonly use consumer-grade routers like the Tenda AC6. Compromise of the router could lead to interception of sensitive communications, unauthorized network access, and lateral movement within corporate networks. This could result in data breaches, disruption of business operations, and exposure to further malware infections or ransomware attacks. Additionally, compromised routers can be enlisted into botnets, contributing to larger scale attacks such as DDoS campaigns that may affect critical infrastructure or services. The lack of a patch and the potential for remote exploitation increase the risk profile. Organizations relying on Tenda AC6 devices should consider the risk of exposure, especially if these devices are used in perimeter network roles or provide VPN or remote access capabilities.

Given the absence of an official patch, European organizations should take immediate steps to mitigate risk. First, isolate Tenda AC6 devices from untrusted networks and restrict management interface access to trusted internal IPs only. Disable remote management features if enabled. Monitor network traffic for unusual patterns that could indicate exploitation attempts. Employ network segmentation to limit the impact of a compromised device. Consider replacing vulnerable devices with routers from vendors with active security support and patch management. Where possible, implement network-level protections such as firewall rules to block access to the vulnerable QoS configuration endpoints. Regularly check for firmware updates from Tenda and apply them promptly once available. Additionally, educate users about the risks of using outdated or unsupported network equipment. For organizations with security monitoring capabilities, deploy IDS/IPS signatures targeting exploitation attempts of this vulnerability once they become available.