CVE-2026-1690 is a remote command injection vulnerability affecting the Tenda HG10 router firmware version US_HG7_HG9_HG10re_300001138_en_xpon. The vulnerability resides in the system function of the /boaform/formSysCmd file, specifically in the handling of the sysCmd parameter. By manipulating this parameter, an attacker can inject arbitrary system commands that the device executes with elevated privileges. The attack vector is network-based and does not require user interaction or authentication, increasing the risk of exploitation. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:H indicates high privileges required, but the description says no authentication is needed, so this may be a discrepancy), no user interaction (UI:N), and low impact on confidentiality, integrity, and availability. Despite the medium severity rating, the ability to execute arbitrary commands remotely on a network device can lead to significant security breaches, including device takeover, network pivoting, and denial of service. No patches or official mitigations have been released, and while no exploits are currently observed in the wild, the public availability of exploit code increases the risk of future attacks.

The exploitation of this vulnerability can allow attackers to execute arbitrary commands on affected Tenda HG10 routers remotely. This can lead to full device compromise, enabling attackers to alter device configurations, intercept or redirect network traffic, deploy malware, or launch further attacks within the internal network. The integrity and availability of the device and connected networks can be severely impacted. Organizations relying on these routers for critical network infrastructure may face service disruptions, data breaches, and loss of control over network traffic. The medium CVSS score reflects limited impact on confidentiality but does not fully capture the potential for network disruption and lateral movement within compromised environments.

1. Immediately isolate affected Tenda HG10 devices from untrusted networks until a patch or firmware update is available. 2. Monitor network traffic for unusual activity originating from or targeting these devices, especially attempts to access /boaform/formSysCmd. 3. Restrict management interfaces to trusted IP addresses and disable remote management features if possible. 4. Implement network segmentation to limit the exposure of vulnerable devices to critical infrastructure. 5. Regularly check Tenda’s official channels for firmware updates or security advisories addressing this vulnerability. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures targeting command injection attempts on the affected endpoint. 7. Consider replacing affected devices with models from vendors with timely security support if patching is delayed.