Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability
Summary
| CVE | CVE-2026-20212 |
|---|---|
| State | PUBLISHED |
| Assigner | cisco |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-02 17:17:31 UTC |
| Updated | 2026-09-03 13:04:38 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.005270000 probability, percentile 0.427830000 (date 2026-09-07)
Problem Types: CWE-1327 | CWE-1327 Binding to an Unrestricted IP Address
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSSV3_1 | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(1) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(2) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(1) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(99w) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3w) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(99x) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3o) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(4) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3p) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(4a) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(2) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3q) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(5) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(3) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3x) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(4g) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(1) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(3r) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(6) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(4) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(4h) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(2) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(7) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(5) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(4g) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(4) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(1) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3t) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(8) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(6) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3s) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3e) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3o) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(1s) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(2) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(3p) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.3(9) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(2s) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(3) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.4(7) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.5(5) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(2n) | Not specified |
| CNA | Cisco | Cisco NX-OS Software | affected 10.6(3s) | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9k-s1... | [email protected] | sec.cloudapps.cisco.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Exploits
CNA: 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.
There are currently no legacy QID mappings associated with this CVE.