CVE-2025-11526 identifies a stack-based buffer overflow vulnerability in the Tenda AC7 router firmware version 15.03.06.44. The flaw exists in an unspecified function handling the /goform/WifiMacFilterSet endpoint, specifically when processing the wifi_chkHz parameter. This parameter manipulation leads to a buffer overflow on the stack, which can be exploited remotely without requiring authentication or user interaction. The vulnerability is critical because it allows attackers to execute arbitrary code or cause a denial of service by crashing the device. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges or user interaction needed. The exploit vector is network-based, targeting the router’s web management interface. Although no exploits have been observed in the wild yet, the public disclosure of exploit code increases the risk of imminent attacks. The vulnerability affects a widely deployed consumer and small business router model, which is often used in home and office environments. The lack of a patch link suggests that a vendor fix may not yet be available, emphasizing the need for interim defensive measures.

For European organizations, this vulnerability poses a significant risk to network security and operational continuity. Compromise of Tenda AC7 routers could allow attackers to gain unauthorized control over network infrastructure, intercept or manipulate traffic, and pivot to internal systems. This is particularly concerning for small and medium enterprises and home offices that rely on these routers without advanced security controls. The potential for remote code execution means attackers could install persistent malware or create backdoors, undermining confidentiality and integrity of sensitive data. Denial of service attacks could disrupt internet connectivity, impacting business operations. Given the router’s role as a network gateway, exploitation could facilitate broader attacks against corporate networks or critical infrastructure. The absence of authentication requirements and user interaction lowers the barrier for attackers, increasing the likelihood of exploitation. European organizations with exposed or poorly secured router management interfaces are at heightened risk.

1. Immediately restrict remote access to the router’s management interface by disabling WAN-side access or limiting it via IP whitelisting and VPNs. 2. Monitor network traffic for unusual requests targeting /goform/WifiMacFilterSet or abnormal patterns indicative of buffer overflow attempts. 3. Apply any available firmware updates from Tenda as soon as they are released; if no patch is available, contact the vendor for guidance or consider temporary device replacement. 4. Implement network segmentation to isolate vulnerable routers from critical systems and sensitive data. 5. Use intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect exploitation attempts. 6. Educate users and administrators about the risk and ensure strong passwords and secure configurations on all network devices. 7. Consider deploying alternative routers with better security track records if patching is delayed. 8. Regularly audit router configurations and firmware versions across the organization to identify and remediate vulnerable devices promptly.