CVE-2026-20212 PUBLISHED

Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability

Assigner: cisco
Reserved: 08.10.2025 Published: 02.09.2026 Updated: 03.09.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 9.8

Product Status

Vendor Cisco
Product Cisco NX-OS Software
Versions Default: unknown
  • Version 10.3(1) is affected
  • Version 10.3(2) is affected
  • Version 10.3(3) is affected
  • Version 10.4(1) is affected
  • Version 10.3(99w) is affected
  • Version 10.3(3w) is affected
  • Version 10.3(99x) is affected
  • Version 10.3(3o) is affected
  • Version 10.3(4) is affected
  • Version 10.3(3p) is affected
  • Version 10.3(4a) is affected
  • Version 10.4(2) is affected
  • Version 10.3(3q) is affected
  • Version 10.3(5) is affected
  • Version 10.4(3) is affected
  • Version 10.3(3x) is affected
  • Version 10.3(4g) is affected
  • Version 10.5(1) is affected
  • Version 10.3(3r) is affected
  • Version 10.3(6) is affected
  • Version 10.4(4) is affected
  • Version 10.3(4h) is affected
  • Version 10.5(2) is affected
  • Version 10.3(7) is affected
  • Version 10.4(5) is affected
  • Version 10.5(3) is affected
  • Version 10.4(4g) is affected
  • Version 10.5(4) is affected
  • Version 10.6(1) is affected
  • Version 10.5(3t) is affected
  • Version 10.3(8) is affected
  • Version 10.4(6) is affected
  • Version 10.5(3s) is affected
  • Version 10.5(3e) is affected
  • Version 10.5(3o) is affected
  • Version 10.6(1s) is affected
  • Version 10.6(2) is affected
  • Version 10.5(3p) is affected
  • Version 10.3(9) is affected
  • Version 10.6(2s) is affected
  • Version 10.6(3) is affected
  • Version 10.4(7) is affected
  • Version 10.5(5) is affected
  • Version 10.6(2n) is affected
  • Version 10.6(3s) is affected

Exploits

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References

Problem Types

  • Binding to an Unrestricted IP Address cwe