CVE-2026-2537 is a command injection vulnerability identified in Comfast CF-E4 firmware version 2.6.0.1. The flaw exists in the HTTP POST request handler component, specifically in the /cgi-bin/mbox-config endpoint with parameters method=SET and section=ntp_timezone. The vulnerability stems from improper validation or sanitization of the 'timestr' argument, which an attacker can manipulate to inject arbitrary system commands. This injection allows remote attackers to execute commands on the device with the privileges of the HTTP service, which requires high privileges (PR:H) but no user interaction (UI:N). The vulnerability has a CVSS 4.0 base score of 5.1, reflecting medium severity, due to the limited scope of impact and the requirement for elevated privileges. The vendor has not issued a patch or response, and public exploit code is available, increasing the risk of exploitation. The attack vector is network-based (AV:N), meaning attackers can exploit it remotely over the network. The vulnerability affects the confidentiality, integrity, and availability of the device by enabling unauthorized command execution, potentially leading to device compromise, data leakage, or denial of service. The lack of vendor response and patch availability increases the urgency for organizations to implement mitigations.

For European organizations, the exploitation of CVE-2026-2537 could lead to unauthorized remote control of Comfast CF-E4 devices, which are often used in wireless networking and IoT deployments. This could result in interception or manipulation of network traffic, disruption of network services, or pivoting to other internal systems. Critical infrastructure sectors such as telecommunications, manufacturing, and public services that rely on these devices for network connectivity may experience operational disruptions or data breaches. The medium severity rating indicates moderate risk; however, the availability of public exploits and lack of vendor patching elevate the threat level. Organizations with large-scale deployments of Comfast devices or those using them in sensitive environments are particularly vulnerable. The impact extends to potential regulatory and compliance issues under GDPR if personal data is compromised due to this vulnerability.

Since no official patch is available, European organizations should implement immediate compensating controls. These include isolating Comfast CF-E4 devices on segmented network zones with strict access controls to limit exposure. Disable or restrict access to the vulnerable /cgi-bin/mbox-config endpoint if possible, using firewall rules or web application firewalls. Monitor network traffic for unusual POST requests targeting the ntp_timezone parameter and set up intrusion detection/prevention systems to alert on suspicious command injection patterns. Regularly audit device firmware versions and configurations to identify vulnerable units. Consider replacing or upgrading devices to models with vendor support and security updates. Additionally, enforce strong authentication and limit administrative access to trusted personnel only. Document and prepare incident response plans specific to potential exploitation scenarios involving these devices.