CVE-2026-23754 is an authorization bypass vulnerability classified under CWE-639, affecting D-Link's D-View 8 network management software versions 2.0.1.107 and earlier. The flaw resides in the backend API endpoints where an authenticated user can supply an arbitrary user_id parameter to retrieve sensitive credential data belonging to other users, including those with super administrator privileges. The vulnerability arises from improper access control checks that fail to validate whether the requesting user is authorized to access the requested user_id data. The exposed credentials can be directly reused as valid authentication tokens, enabling full impersonation of the targeted accounts without additional authentication or user interaction. This leads to complete account takeover, granting attackers full administrative control over the D-View system, which is critical for managing network devices. The CVSS 4.0 base score is 8.7, reflecting high severity due to network exploitability, low attack complexity, no privileges beyond authentication, no user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently in the wild, the vulnerability poses a significant risk to organizations relying on D-View 8 for network management, as attackers can manipulate network configurations, disrupt operations, or exfiltrate sensitive data. The lack of available patches at the time of disclosure necessitates immediate compensating controls to mitigate risk.

For European organizations, the impact of CVE-2026-23754 is substantial. D-View 8 is used for centralized network management, and a compromise of administrative accounts can lead to unauthorized changes in network configurations, exposure of sensitive network credentials, and potential disruption of critical infrastructure. Confidentiality is severely impacted as attackers can access credential data of privileged users. Integrity is compromised because attackers can alter network device configurations, potentially inserting backdoors or disabling security controls. Availability is also at risk if attackers disrupt network management functions or cause denial of service through misconfiguration. Given the critical role of network management in sectors such as finance, telecommunications, government, and critical infrastructure, the vulnerability could facilitate lateral movement, espionage, or sabotage. European organizations with limited segmentation between management and user networks are particularly vulnerable. The absence of known exploits currently provides a window for proactive defense, but the ease of exploitation and high impact necessitate urgent attention.

1. Immediately restrict access to D-View 8 backend API endpoints to trusted administrative networks and users only, using network segmentation and firewall rules. 2. Implement strict authentication and authorization checks at the API level, ensuring users can only access their own credential data. 3. Monitor logs for unusual API requests involving user_id parameters, especially those requesting credentials of other users or administrators. 4. Enforce multi-factor authentication (MFA) for all D-View 8 user accounts to reduce risk from credential compromise. 5. Regularly audit user accounts and permissions within D-View 8 to detect unauthorized privilege escalations. 6. Coordinate with D-Link for timely patch deployment once available; in the meantime, consider temporary disabling of vulnerable API features if feasible. 7. Educate network administrators about the vulnerability and encourage vigilance for suspicious activity. 8. Employ intrusion detection systems (IDS) tuned to detect anomalous API usage patterns related to this vulnerability. 9. Backup current configurations and credentials securely to enable rapid recovery if compromise occurs.