cisco-sa-n9k-s1-rce-EH8dEtr: Cisco Nexus 9000 Series Switches Silicon One Remote Code Execution Vulnerability

Published Sep 2, 2026
·
Updated

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.Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9k-s1-rce-EH8dEtr

Affected Software

1 affected component
Cisco Cisco Nexus 9000 Series Switches

Event History

Sep 2, 2026
Advisory Published
via Cisco·04:00 PM
Data Sourced
via Cisco·04:00 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What access does an attacker need to exploit this issue?

An attacker does not need to authenticate. They need remote network access to an affected device and the ability to connect to TCP port 43210 or 43211.

2

Are devices exposed in the default configuration?

The vulnerable TCP ports are accessible in the default Layer 3 virtual routing and forwarding (VRF) configuration. Teams should determine whether untrusted networks can reach ports 43210 or 43211 on affected switches.

3

What is the potential operational impact besides code execution?

Crafted input can be executed with root privileges. Exploitation may also crash the S1HAL process and cause the device to reload.

4

What can be done if updates cannot be applied immediately?

Cisco has released software updates and states that workarounds are available. Until updates can be applied, use the available workarounds and restrict network access to TCP ports 43210 and 43211.

Contact

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