A vulnerability in the Silicon One integration for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to execute code with root privileges. This vulnerability exists because TCP ports 43210 and 43211 are accessible in the default Layer 3 (L3) virtual routing and forwarding (VRF). A successful exploit could allow the attacker to connect to an affected device and send crafted input that could be executed as code with root privileges. The exploitation of this vulnerability could also cause the S1HAL process to crash, which could cause the device to reload.

A critical vulnerability (CVE-2026-20212) has been identified in the Silicon One integration for Cisco Nexus 9000 Series Switches. The flaw allows an unauthenticated, remote attacker to execute arbitrary code with root privileges. The vulnerability stems from TCP ports 43210 and 43211 being accessible in the default Layer 3 (L3) virtual routing and forwarding (VRF). An attacker can connect to an affected device and send crafted input that executes as root-level code. Additionally, exploitation can cause the S1HAL process to crash, potentially forcing the device to reload. No authentication is required to exploit this vulnerability, making it particularly dangerous in exposed network environments. The issue is tracked under CVE-2026-20212 and has been published by both NVD and Cisco's Security Advisory portal.