CVE-2026-2911 is a buffer overflow vulnerability identified in the Tenda FH451 router firmware versions 1.0.0.0 through 1.0.0.9. The vulnerability arises from improper handling of input data sent to the /goform/GstDhcpSetSer endpoint, which is part of the router's DHCP server configuration interface. An attacker can remotely send specially crafted requests to this endpoint, causing a buffer overflow condition. This overflow can corrupt memory, potentially allowing the attacker to execute arbitrary code with elevated privileges or cause the device to crash, resulting in denial of service. The vulnerability does not require authentication or user interaction, making it exploitable over the network by any remote attacker. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). Although no exploits have been observed in the wild yet, the public disclosure of the vulnerability increases the likelihood of exploitation attempts. The lack of available patches at the time of disclosure necessitates immediate mitigation efforts by affected users. This vulnerability is critical for environments relying on Tenda FH451 routers for network connectivity, especially where these devices are exposed to untrusted networks.

The impact of CVE-2026-2911 is significant for organizations using Tenda FH451 routers. Successful exploitation can lead to full compromise of the device, allowing attackers to execute arbitrary code, manipulate network traffic, intercept sensitive data, or disrupt network availability through denial of service. This can undermine the confidentiality, integrity, and availability of the entire network segment relying on the router. For enterprises, this could mean unauthorized access to internal systems, data breaches, or operational outages. In critical infrastructure or industrial environments, compromised routers could be leveraged to pivot attacks deeper into the network or disrupt essential services. The remote and unauthenticated nature of the exploit increases the attack surface, making it easier for threat actors to target vulnerable devices at scale. The absence of known exploits in the wild currently provides a limited window for proactive defense before potential exploitation campaigns emerge.

To mitigate CVE-2026-2911, organizations should immediately identify all Tenda FH451 devices running affected firmware versions. Since no official patches are currently available, temporary mitigations include restricting network access to the router's management interfaces by implementing strict firewall rules and network segmentation to isolate these devices from untrusted networks. Disable remote management features if enabled, especially access to the /goform/GstDhcpSetSer endpoint. Monitor network traffic for unusual requests targeting this endpoint and implement intrusion detection/prevention systems (IDS/IPS) signatures to detect exploitation attempts. Regularly check for firmware updates from Tenda and apply patches as soon as they are released. Additionally, consider replacing vulnerable devices with models from vendors with more robust security update practices if long-term support is uncertain. Conduct security awareness training for network administrators to recognize and respond to exploitation indicators promptly.