CVE-2026-20212CWE-1327

CVE-2026-20212

Critical · published September 2, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
42.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00527 · 42.7th percentile
Weakness
CWE-1327 · Binding to an Unrestricted IP Address
Published
2026-09-02T21:17Z
References (1)
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n9k-s1-rce-EH8dEtr · [email protected]
EPSS history
Timeline
  • 04 SEP 03:39Z
    EPSS moved — → 1%
    epss
  • 02 SEP 16:13Z
    Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability
    cvelistv5