CVE-2026-0403 identifies a security vulnerability in the NETGEAR Orbi RBR750 router, specifically an improper input validation issue classified under CWE-20. This vulnerability allows an attacker who is connected to the router's local area network (LAN) to inject and execute arbitrary operating system commands on the device. The root cause is insufficient validation of inputs that are processed by the router, which can be exploited to run OS commands, potentially compromising the router's integrity and control. The vulnerability requires the attacker to have high privileges on the LAN (e.g., authenticated access or elevated rights), and no user interaction is necessary to trigger the exploit. The CVSS 4.0 base score is 1.1, indicating a low severity primarily due to the requirement for local access and high privileges, as well as limited impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild, and no official patches or updates have been published by NETGEAR at the time of this report. The affected product is the RBR750 model of NETGEAR Orbi routers, which are commonly used in enterprise and home network environments for Wi-Fi mesh networking. The vulnerability could allow attackers to gain control over the router, potentially leading to network disruption or further lateral movement within the LAN. The lack of remote attack vector and the need for high privileges limit the scope of exploitation but do not eliminate the risk in environments where internal threats or compromised devices exist.

For European organizations, the impact of CVE-2026-0403 is primarily related to internal network security. If an attacker gains access to the LAN, they could exploit this vulnerability to execute arbitrary commands on the router, potentially leading to unauthorized control over network traffic, disruption of network services, or use of the router as a pivot point for further attacks within the network. This could affect confidentiality by intercepting or redirecting traffic, integrity by altering router configurations, and availability by causing denial of service. The low CVSS score reflects the limited risk for external attackers, but insider threats or compromised internal devices could leverage this vulnerability. Organizations with critical infrastructure or sensitive data relying on NETGEAR Orbi RBR750 routers may face increased risk, especially if network segmentation and access controls are weak. The absence of known exploits reduces immediate threat but does not preclude future exploitation. Overall, the vulnerability could degrade network security posture and increase the attack surface if not mitigated.

To mitigate CVE-2026-0403, European organizations should implement strict network segmentation to limit LAN access only to trusted devices and users. Enforce strong authentication and access control policies on the router and internal networks to prevent unauthorized privilege escalation. Monitor network traffic and router logs for unusual command execution or configuration changes indicative of exploitation attempts. Disable or restrict administrative interfaces on the LAN side where possible. Apply any future firmware updates or patches from NETGEAR promptly once available. Consider deploying intrusion detection/prevention systems (IDS/IPS) that can detect command injection patterns or anomalous router behavior. Conduct regular security audits and vulnerability assessments on network devices to identify and remediate similar issues proactively. Educate internal users about the risks of connecting unauthorized devices to the LAN. Finally, maintain an inventory of all NETGEAR Orbi RBR750 devices to ensure comprehensive coverage of mitigation efforts.