Description

Cisco has disclosed a high-severity vulnerability identified as CVE-2026-20188 affecting Cisco Crosswork Network Controller (CNC) and Network Services Orchestrator (NSO) platforms. The flaw can allow remote attackers to exhaust system connections and disrupt critical network management operations, resulting in denial-of-service conditions. Successful exploitation may prevent legitimate users and automated orchestration services from accessing affected systems, potentially impacting enterprise and telecom network environments globally. The vulnerability exists because the affected platforms improperly handle incoming connection requests, allowing attackers to repeatedly send specially crafted requests that consume available system resources. Once resources are exhausted, the affected services may become unstable or unavailable. Since Cisco NSO and Crosswork solutions are commonly used for centralized network automation and provisioning, exploitation of this flaw could interrupt operational workflows, delay network changes, and affect infrastructure visibility in large-scale environments. Organizations are advised to immediately apply Cisco’s latest security patches and fixed software releases. Access to management and orchestration interfaces should be restricted to trusted networks using segmentation, VPNs, and access control lists. Security teams should also monitor systems for unusual spikes in connection requests, enable logging for abnormal activity, and implement high-availability configurations to minimize operational disruption if attacks occur.