CVE-2026-2180 is a stack-based buffer overflow vulnerability identified in the Tenda RX3 router firmware version 16.03.13.11. The flaw exists in an unspecified function within the /goform/fast_setting_wifi_set endpoint, specifically triggered by manipulation of the ssid_5g parameter. When this parameter is crafted maliciously, it causes a stack buffer overflow, enabling an attacker to overwrite memory on the stack. This can lead to arbitrary code execution, potentially allowing full control over the device. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P) reflects network attack vector, low complexity, no authentication, and high impact on confidentiality, integrity, and availability. While no active exploitation in the wild has been reported, a public exploit is available, increasing the likelihood of attacks. The Tenda RX3 is commonly used in home and small office environments, often serving as a gateway device, which if compromised, can provide attackers a foothold into internal networks. The lack of vendor patch links indicates that a fix may not yet be available, emphasizing the need for interim mitigations.

For European organizations, exploitation of CVE-2026-2180 could result in complete compromise of affected Tenda RX3 routers, leading to unauthorized access to internal networks, interception or manipulation of network traffic, and potential lateral movement to other critical systems. This threatens confidentiality through data leakage, integrity through unauthorized modifications, and availability by causing device crashes or persistent backdoors. Small and medium enterprises relying on Tenda RX3 for network connectivity are particularly vulnerable due to limited security monitoring. Critical infrastructure sectors using these devices could face operational disruptions or espionage. The remote and unauthenticated nature of the exploit increases the risk of widespread attacks, especially in environments with exposed management interfaces. The presence of a public exploit lowers the barrier for attackers, including cybercriminals and nation-state actors, to weaponize this vulnerability against European targets.

1. Immediately check for and apply any official firmware updates from Tenda addressing CVE-2026-2180. 2. If patches are unavailable, restrict access to the router’s management interfaces by implementing network segmentation and firewall rules to block external access to /goform/fast_setting_wifi_set endpoints. 3. Employ deep packet inspection (DPI) or intrusion prevention systems (IPS) to detect and block malformed ssid_5g parameter payloads indicative of exploitation attempts. 4. Disable remote management features on Tenda RX3 devices unless absolutely necessary, and if enabled, restrict access to trusted IP addresses only. 5. Monitor network traffic and device logs for unusual activity or signs of compromise related to this vulnerability. 6. Consider replacing vulnerable Tenda RX3 devices with models from vendors with a stronger security track record if patches are delayed. 7. Educate IT staff on the risks and detection methods for buffer overflow exploits targeting network devices.