CVE-2026-20212
Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability
Description
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.
Weakness: CWE-1327
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco NX-OS Software | Routing & Switching | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco NX-OS Software
Vendor advisory
Cisco Nexus 9000 Series Switches Silicon One Remote Code Execution Vulnerability
Cisco’s rating: Critical (advisory CVSS 9.8) · Published Sep 2, 2026
Bug ID: CSCwu32817
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from