CVE-2026-24439 identifies a vulnerability in the Shenzhen Tenda W30E V2 router firmware (up to version V16.01.0.19(5037)) where the web management interface fails to include the HTTP response header X-Content-Type-Options with the value 'nosniff'. This header instructs browsers to strictly follow the declared Content-Type and prevents MIME sniffing, a process where browsers attempt to determine the content type of a resource based on its content rather than the declared header. Without this header, browsers may incorrectly interpret attacker-influenced responses as executable scripts, potentially leading to cross-site scripting (XSS) or other injection attacks. The vulnerability is categorized under CWE-116 (Improper Encoding or Escaping of Output). The CVSS 4.0 base score is 2.1, indicating low severity, with attack vector as network (remote), high attack complexity, partial attack prerequisites, no privileges required, user interaction needed, and low impact on confidentiality and integrity. No known exploits are currently reported in the wild, and no patches have been published yet. The vulnerability primarily affects the confidentiality and integrity of the device management interface by enabling potential script execution in the context of the router's web interface, which could be leveraged to steal credentials or manipulate device settings if exploited.

For European organizations, this vulnerability poses a low but tangible risk, especially for those deploying Shenzhen Tenda W30E V2 routers in their network infrastructure. If the management interface is accessible from internal or external networks, attackers could craft malicious web responses that browsers misinterpret as executable scripts, potentially leading to credential theft or unauthorized configuration changes. This could compromise network security, leading to further lateral movement or data exfiltration. The impact is limited by the requirement for user interaction and the high complexity of attack execution. However, in environments with less stringent network segmentation or where users frequently access router management interfaces, the risk increases. The absence of the nosniff header also weakens the overall security posture against MIME sniffing attacks, which can be combined with other vulnerabilities for more severe exploitation. Given the widespread use of Tenda networking equipment in some European markets, organizations should assess exposure and implement compensating controls to mitigate potential impacts.

1. Restrict access to the router's web management interface by limiting it to trusted internal networks and using strong authentication mechanisms. 2. Implement network segmentation to isolate management interfaces from general user networks and the internet. 3. Monitor network traffic and logs for unusual or suspicious activity targeting the router's management interface. 4. Educate users about the risks of interacting with unsolicited or suspicious links that could trigger malicious scripts. 5. Regularly check for firmware updates from Shenzhen Tenda and apply patches promptly once available to address this and other vulnerabilities. 6. Consider deploying web application firewalls (WAFs) or intrusion detection/prevention systems (IDS/IPS) that can detect and block attempts to exploit MIME sniffing or script injection attacks. 7. If possible, configure custom HTTP headers on the device or via reverse proxies to include X-Content-Type-Options: nosniff as a temporary mitigation until official patches are released.