by Kastro
Paper/Archive/CVE-2026-20212

CVE-2026-20212

Cisco Cisco NX-OS Software — Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability

EPSS 0.8%CVSS 9.8
critical.is priorityof 100
41
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 57.6.576 × 2011.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Cisco NX-OS Software10.3(1)–CNA
Cisco NX-OS Software10.3(2)–CNA
Cisco NX-OS Software10.3(3)–CNA
Cisco NX-OS Software10.4(1)–CNA
Cisco NX-OS Software10.3(99w)–CNA
Cisco NX-OS Software10.3(3w)–CNA
Cisco NX-OS Software10.3(99x)–CNA
Cisco NX-OS Software10.3(3o)–CNA
Cisco NX-OS Software10.3(4)–CNA
Cisco NX-OS Software10.3(3p)–CNA
Cisco NX-OS Software10.3(4a)–CNA
Cisco NX-OS Software10.4(2)–CNA

Scores by source

cisco (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refsec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9k-s1-rce-EH8dEtr