CVE-2026-2856 is a stack-based buffer overflow vulnerability identified 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. The vulnerability is triggered by manipulating the 'submit-url' argument, which leads to an overflow of the stack buffer. This overflow can corrupt adjacent memory, potentially allowing an attacker to execute arbitrary code remotely. The vulnerability requires no authentication or user interaction, making it highly exploitable over the network. The CVSS 4.0 score of 8.7 reflects its high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although no confirmed exploitation in the wild has been reported, public availability of exploit code increases the risk of imminent attacks. The vulnerability affects only firmware version 1.01.07 of the DWR-M960 model, emphasizing the need for firmware updates or alternative mitigations. The lack of official patches at the time of disclosure necessitates immediate defensive measures to reduce exposure.

The exploitation of CVE-2026-2856 can have severe consequences for organizations globally. Successful attacks can lead to remote code execution with elevated privileges on affected D-Link DWR-M960 routers, compromising device integrity and control. This can result in unauthorized network access, interception or manipulation of network traffic, and potential pivoting to internal networks. Confidential data passing through the device may be exposed or altered, and availability may be disrupted by device crashes or malicious payloads. Given the router's role in network infrastructure, compromised devices can serve as entry points for broader attacks, including lateral movement and persistent threats. The absence of authentication and user interaction requirements significantly increases the attack surface. Organizations relying on this router model for critical connectivity or in sensitive environments face heightened risks of operational disruption and data breaches.

To mitigate CVE-2026-2856, organizations should immediately verify if they are running D-Link DWR-M960 firmware version 1.01.07 and prioritize upgrading to a patched firmware version once released by D-Link. In the absence of an official patch, network administrators should restrict access to the router's management interfaces by implementing network segmentation and firewall rules to limit exposure to trusted IP addresses only. Disabling remote management features and filtering inbound traffic targeting the /boafrm/formFilter endpoint can reduce attack vectors. Monitoring network traffic for anomalous requests containing suspicious 'submit-url' parameters is advised. Employing intrusion detection/prevention systems (IDS/IPS) with signatures tailored to detect exploitation attempts can provide additional protection. Regularly auditing device configurations and maintaining up-to-date inventories of network equipment will facilitate rapid response. Finally, organizations should engage with D-Link support channels to obtain updates and advisories promptly.