CVE-2026-2856 identifies a stack-based buffer overflow vulnerability in the D-Link DWR-M960 router firmware version 1.01.07. The flaw resides in the Filter Configuration Endpoint component, specifically within the function sub_424AFC located in the /boafrm/formFilter file. An attacker can exploit this vulnerability by sending a specially crafted request manipulating the 'submit-url' parameter, which leads to a stack-based buffer overflow condition. This type of overflow can overwrite the return address or other control data on the stack, enabling remote code execution with elevated privileges on the device. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 base score is 8.7, reflecting high severity due to the ease of exploitation and the potential for full system compromise. Although no active exploits have been reported in the wild, the public disclosure of exploit code increases the likelihood of attacks. The vulnerability affects only firmware version 1.01.07 of the DWR-M960, so devices running other versions may not be vulnerable. No official patches or updates have been linked yet, so mitigation relies on network-level protections and vendor advisories. This vulnerability threatens the confidentiality, integrity, and availability of affected routers, which often serve as critical network gateways in home and enterprise environments.

The exploitation of CVE-2026-2856 can lead to complete compromise of affected D-Link DWR-M960 routers, allowing attackers to execute arbitrary code remotely with elevated privileges. This can result in unauthorized access to internal networks, interception or manipulation of network traffic, disruption of network services, and potential pivoting to other connected systems. For organizations, this means exposure of sensitive data, loss of network availability, and potential damage to operational continuity. Since the vulnerability requires no authentication or user interaction, attackers can scan for vulnerable devices and launch automated attacks at scale. The impact is particularly severe for enterprises and service providers relying on these routers for secure internet connectivity. Additionally, compromised routers could be recruited into botnets or used as launch points for further attacks, amplifying the threat landscape. The absence of patches increases the window of exposure, making timely mitigation critical.

1. Immediately isolate and restrict network access to affected D-Link DWR-M960 devices running firmware version 1.01.07, especially from untrusted networks. 2. Monitor network traffic for unusual or suspicious requests targeting the /boafrm/formFilter endpoint and the submit-url parameter. 3. Implement network-level protections such as web application firewalls (WAFs) or intrusion prevention systems (IPS) with signatures to detect and block exploit attempts targeting this vulnerability. 4. Contact D-Link support or check official channels regularly for firmware updates or patches addressing CVE-2026-2856 and apply them promptly once available. 5. If patching is not immediately possible, consider temporary mitigations such as disabling remote management interfaces or restricting access to trusted IP addresses only. 6. Conduct thorough audits of affected devices to detect any signs of compromise and perform incident response if necessary. 7. Educate network administrators about this vulnerability and ensure they follow secure configuration best practices to minimize attack surface.