Cisco NX-OS Software NX-API Remote Code Execution Vulnerability

Description

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to execute arbitrary code with root privileges or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation of data that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API of an affected device. A successful exploit could allow the attacker to execute arbitrary code with root privileges and could cause process crashes, which could result in a reload of the device and a DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-napi-rce-r2shwu2j This advisory is part of a group of advisories. For a complete list of the advisories and links to them, see Cisco Advance Notification for Publication of October 7, 2026, Security Advisories . For further documentation of improvements and fixes in Cisco NX-OS Software, see Cisco NX-OS Software Security Hardening Release: October 2026 . Security Impact Rating: Critical CVE: CVE-2026-76471

What to do

Install the fixed versions listed in the official advisory. If you cannot update right away, apply the workarounds or mitigations it describes and limit access to the affected service.

Details

Vendor

Cisco

Product

Cisco NX-OS

CVE

CVE-2026-76471

Affected versions

Cisco NX-OS Software 9.2: 7 versions, from 9.2(3) to 9.2(2)
Cisco NX-OS Software 9.3: 21 versions, from 9.3(2) to 9.3(17)
Cisco NX-OS Software 10.3: 20 versions, from 10.3(1) to 10.3(9)
Cisco NX-OS Software 10.4: 8 versions, from 10.4(1) to 10.4(7)
Cisco NX-OS Software 10.5: 10 versions, from 10.5(1) to 10.5(5)
Cisco NX-OS Software 10.6: 7 versions, from 10.6(1) to 10.6(3s)
Cisco Unified Computing System (Managed) 4.0: 22 versions, from 4.0(1a) to 4.0(4o)
Cisco Unified Computing System (Managed) 4.1: 22 versions, from 4.1(1d) to 4.1(3n)
Cisco Unified Computing System (Managed) 4.2: 27 versions, from 4.2(1c) to 4.2(3s)
Cisco Unified Computing System (Managed) 4.3: 25 versions, from 4.3(2b) to 4.3(6i) (from the advisory and NVD; check the exact builds in the official advisory)

CVSS score

9.8

Actively exploited

Not known at this time

Source

Cisco PSIRT – original advisory

Published

October 8, 2026

The description and the recommended action are quoted from the public advisory (the action is our generic advice); severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.