Cisco NX-OS Software Control Plane Denial of Service Vulnerability
MonitorCVSS 5.8cisco-sa-nxos-nscpdos-SnderkC7Oct 7, 2026
CiscoTransportation
IT in OT - Cisco networking products are commonly deployed in OT environments
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary
A vulnerability in Cisco NX-OS Software allows an unauthenticated remote attacker to exhaust system resources by sending high-rate UDP or TCP connections to data plane interfaces, causing temporary disruptions to routing and control plane protocols. The DoS condition clears automatically when the attack traffic stops. Cisco has released software updates to address this vulnerability.
What this means
What could happen
An attacker can send high-rate UDP or TCP traffic to a network switch, temporarily overloading the control plane and disrupting routing protocols until traffic stops. This could cause brief loss of connectivity or packet loss in your network.
Who's at risk
Network operators running Cisco Nexus 3000, 7000, and 9000 Series switches who rely on consistent control plane performance. This affects any organization using these switches in production networks, especially in transportation, energy, and other critical infrastructure sectors where network availability is essential.
How it could be exploited
An attacker on the network sends a sustained high rate of UDP or TCP packets to a data plane interface on an affected Cisco Nexus switch. The switch lacks proper rate limiting on these protocols, causing the control plane to become overwhelmed, disrupting routing protocols and causing temporary network instability.
Prerequisites
- Network access to at least one data plane interface (non-management) on the affected switch
- No authentication required
remotely exploitableno authentication requiredlow complexityaffects network control systems
Exploitability
Unlikely to be exploited — EPSS score 0.4%
Affected products (3)
3 with fix
ProductAffected VersionsFix Status
Nexus 3000 Series SwitchesAll versionsFix available
Nexus 9000 Series SwitchesAll versionsFix available
Nexus 7000 Series SwitchesAll versionsFix available
Remediation & Mitigation
0/2
Schedule — requires maintenance window
0/1Patching may require device reboot — plan for process interruption
HOTFIXUpdate Cisco NX-OS firmware on Nexus 3000, 7000, and 9000 Series switches to the patched version released in October 2026
Long-term hardening
0/1HARDENINGImplement network segmentation and firewall rules to restrict which networks can send traffic to switch data plane interfaces
CVEs (1)
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