CVE-2026-2535 is a remote command injection vulnerability affecting Comfast CF-N1 V2 devices running firmware version 2.6.0.2. The vulnerability resides in the CGI script endpoint /cgi-bin/mbox-config, specifically in the function sub_44AB9C, which processes the 'channel' parameter when the method is SET and section is ptest_channel. Improper input validation allows an attacker to inject arbitrary shell commands by manipulating the 'channel' argument. This flaw enables remote attackers to execute commands with the privileges of the web server process, potentially leading to full device compromise. The attack requires no authentication or user interaction, increasing its risk. The vendor was notified early but has not issued any response or patch, leaving devices exposed. While no known exploits have been observed in the wild, public proof-of-concept code exists, increasing the likelihood of exploitation. The vulnerability's CVSS 4.0 score is 5.3, reflecting medium severity due to limited privileges and impact scope, but the ability to execute arbitrary commands remotely remains a serious concern. The lack of vendor response and patch availability necessitates immediate defensive measures by users.

The vulnerability allows remote attackers to execute arbitrary commands on affected Comfast CF-N1 V2 devices, potentially leading to full device compromise. This can result in unauthorized access to network infrastructure, interception or manipulation of network traffic, and pivoting to other internal systems. The integrity and availability of the device and connected networks may be severely impacted. Attackers could deploy malware, create persistent backdoors, or disrupt wireless communications. Given the device's role in wireless networking, exploitation could degrade or disable critical connectivity, affecting business operations. The absence of vendor patches increases exposure time, raising the risk of widespread exploitation, especially in environments where these devices are deployed at scale. Organizations relying on these devices face risks to confidentiality, integrity, and availability of their network services.

Since no official patch or vendor response is available, organizations should implement immediate compensating controls. First, restrict network access to the management interface of Comfast CF-N1 V2 devices by applying firewall rules or network segmentation to limit exposure to trusted administrators only. Disable or restrict access to the vulnerable CGI endpoint if possible, or apply web application firewall (WAF) rules to detect and block suspicious requests targeting /cgi-bin/mbox-config with the method=SET and section=ptest_channel parameters. Monitor device logs and network traffic for unusual activity indicative of exploitation attempts. Consider replacing or upgrading affected devices to models with vendor support and security updates. If feasible, isolate vulnerable devices on separate VLANs to minimize potential lateral movement. Regularly review and update device firmware when vendor patches become available. Employ intrusion detection/prevention systems (IDS/IPS) tuned to detect command injection patterns targeting this device.