Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability (CVE-2026-20212) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-20212

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

Answer in brief

CVE-2026-20212 records a Unknown severity vulnerability in Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco NX-OS Software (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 2, 2026Updated Sep 2, 2026Source checked Sep 2, 2026First seen by HOL Sep 2, 2026Material review Sep 2, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Cisco/Cisco NX-OS Software (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Cisco/Cisco NX-OS Softwaregeneric	10.3(1) \|\| 10.3(2) \|\| 10.3(3) \|\| 10.4(1) \|\| 10.3(99w) \|\| 10.3(3w) \|\| 10.3(99x) \|\| 10.3(3o) \|\| 10.3(4) \|\| 10.3(3p) \|\| 10.3(4a) \|\| 10.4(2) \|\| 10.3(3q) \|\| 10.3(5) \|\| 10.4(3) \|\| 10.3(3x) \|\| 10.3(4g) \|\| 10.5(1) \|\| 10.3(3r) \|\| 10.3(6) \|\| 10.4(4) \|\| 10.3(4h) \|\| 10.5(2) \|\| 10.3(7) \|\| 10.4(5) \|\| 10.5(3) \|\| 10.4(4g) \|\| 10.5(4) \|\| 10.6(1) \|\| 10.5(3t) \|\| 10.3(8) \|\| 10.4(6) \|\| 10.5(3s) \|\| 10.5(3e) \|\| 10.5(3o) \|\| 10.6(1s) \|\| 10.6(2) \|\| 10.5(3p) \|\| 10.3(9) \|\| 10.6(2s) \|\| 10.6(3) \|\| 10.4(7) \|\| 10.5(5) \|\| 10.6(2n) \|\| 10.6(3s)	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Cisco/Cisco NX-OS Software.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 2, 2026

Sources and claim methodology

Source referencesec.cloudapps.cisco.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.