CVE-2026-2961 is a stack-based buffer overflow vulnerability identified in the D-Link DWR-M960 router firmware version 1.01.07. The vulnerability exists in the function sub_4196C4 within the /boafrm/formVpnConfigSetup component, which handles VPN configuration requests. Specifically, the issue arises from improper validation and handling of the 'submit-url' parameter, which can be manipulated by a remote attacker to overflow the stack buffer. This overflow can overwrite the return address or other control data on the stack, enabling arbitrary code execution with the privileges of the affected process. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 score of 8.7 reflects the ease of exploitation (network vector, low attack complexity), the absence of required privileges or user interaction, and the high impact on confidentiality, integrity, and availability. Although no known exploits are currently active in the wild, public disclosure of exploit code increases the likelihood of imminent attacks. The affected device is commonly used in enterprise and small business environments for VPN connectivity, making it an attractive target for attackers seeking to gain persistent network access or disrupt operations.

The exploitation of CVE-2026-2961 can have severe consequences for organizations worldwide. Successful attacks can lead to remote code execution on the D-Link DWR-M960 device, allowing attackers to take full control of the router. This can result in interception and manipulation of VPN traffic, unauthorized network access, and potential lateral movement within corporate networks. Confidential data transmitted through the VPN can be compromised, and attackers may disrupt network availability by crashing or destabilizing the device. Given the router's role as a VPN gateway, compromise can undermine the security perimeter, exposing internal resources to external threats. Organizations relying on this device for secure remote access face risks of data breaches, espionage, and operational disruption. The public availability of exploit code further elevates the threat, increasing the likelihood of automated or targeted attacks.

To mitigate CVE-2026-2961, organizations should immediately verify if they are using the affected D-Link DWR-M960 firmware version 1.01.07 and upgrade to a patched firmware version once released by D-Link. In the absence of an official patch, administrators should disable the VPN Configuration Endpoint (/boafrm/formVpnConfigSetup) if it is not essential, or restrict access to it via firewall rules limiting connections to trusted management networks. Network segmentation should be enforced to isolate VPN devices from critical infrastructure. Continuous monitoring for anomalous traffic targeting the vulnerable endpoint is advised, including inspecting logs for unusual 'submit-url' parameter usage. Employing intrusion detection/prevention systems (IDS/IPS) with signatures for buffer overflow attempts against this device can provide early warning. Additionally, enforcing strict access controls and using multi-factor authentication for device management interfaces can reduce exploitation risk. Regular security audits and vulnerability assessments should be conducted to ensure no residual exposure remains.