CVE-2026-2151 is an OS command injection vulnerability identified in the D-Link DIR-615 router firmware version 4.10, specifically within the adv_firewall.php script that handles the DMZ Host feature. The vulnerability arises from insufficient validation or sanitization of the dmz_ipaddr parameter, which an attacker can manipulate to inject arbitrary operating system commands. This flaw allows remote attackers to execute commands on the underlying system with high privileges, potentially leading to full device compromise. The attack vector is network-based, requiring no user interaction, but does require authentication with high privileges, possibly administrative access to the device's web interface. The vulnerability affects only devices that are no longer supported by D-Link, meaning no official patches or firmware updates are available. Although no known exploits have been observed in the wild, the public disclosure of the vulnerability increases the likelihood of exploitation attempts. The CVSS v4.0 score of 8.6 reflects the high impact on confidentiality, integrity, and availability, combined with the ease of exploitation once authenticated. This vulnerability could allow attackers to manipulate firewall settings, intercept or redirect traffic, or use the compromised router as a foothold for further network attacks.

The impact of CVE-2026-2151 is significant for organizations using the affected D-Link DIR-615 routers. Successful exploitation could lead to full compromise of the router, allowing attackers to execute arbitrary commands with high privileges. This can result in unauthorized access to internal networks, interception or modification of network traffic, disruption of network availability, and potential lateral movement to other systems. Since the device is a network gateway, compromise could undermine the security posture of the entire network. The lack of vendor support and patches increases the risk, as organizations cannot remediate via firmware updates. This vulnerability could be exploited in targeted attacks against enterprises, small businesses, or home users relying on these routers, especially in environments where network segmentation is weak. The public disclosure may lead to the development of automated exploit tools, increasing the threat landscape.

Given the absence of official patches due to end-of-life status, organizations should prioritize replacing affected D-Link DIR-615 devices with supported hardware that receives regular security updates. In the interim, network administrators should restrict access to the router's management interface, limiting it to trusted internal networks and using strong authentication mechanisms. Disabling the DMZ Host feature entirely can mitigate the attack vector. Network segmentation should be enforced to isolate vulnerable devices from critical assets. Monitoring network traffic for unusual activity and employing intrusion detection systems can help detect exploitation attempts. If replacement is not immediately feasible, consider deploying firewall rules to block external access to the router's management ports and regularly audit device configurations. Additionally, educating users about the risks of using unsupported hardware is essential.