New Cisco Network Vulnerability Let Remote Attacker Cause DoS Attack

Cisco has issued a critical security advisory regarding a high-severity vulnerability impacting its Crosswork Network Controller (CNC) and Network Services Orchestrator (NSO).

Tracked formally as CVE-2026-20188 with a CVSS base score of 7.5, this flaw poses a significant risk to network infrastructure.

If successfully exploited, the vulnerability allows unauthenticated, remote attackers to trigger a severe Denial-of-Service (DoS) condition on targeted systems.

It is classified as an uncontrolled resource consumption issue (CWE-400). Specifically, the vulnerable systems fail to implement adequate rate-limiting controls on incoming network connections.

Malicious actors can leverage this vulnerability by deliberately flooding an affected server with a high volume of continuous connection requests.

Because the software cannot properly throttle these incoming requests, an attacker can quickly exhaust all available connection resources.

Once the system reaches this…