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Cisco Releases NX-OS Software Security Hardening Guidance

The critical advisory addresses multiple vulnerability classes affecting Cisco NX-OS software deployments

Threat ID:
CC-4864
Threat Severity:
Medium
Published:
9 October 2026 11:11 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

The critical advisory addresses multiple vulnerability classes affecting Cisco NX-OS software deployments

Threat details

Introduction

Cisco has published a security hardening advisory for Cisco NX-OS Software following a comprehensive internal security review. The update addresses multiple vulnerability classes including improper neutralization, improper access control, improper input validation, out-of-bounds read, improper handling of exceptional conditions, out-of-bounds write, and heap-based buffer overflow vulnerabilities.

To streamline disclosure, Cisco grouped vulnerabilities according to their underlying Common Weakness Enumeration (CWE) category and assigned a single CVE identifier to each group. Several of the vulnerability classes have high severity ratings, with the two most severe vulnerabilities carrying a CVSS score of 9.8.

Vulnerability Details

  • CVE-2026-76453 - 'Improper neutralization' vulnerability - CVSSv3.1 score of 8.8
  • CVE-2026-76455 - 'Improper access control' vulnerability - CVSSv3.1 score of 9.8
  • CVE-2026-76456 - 'Improper input validation' vulnerability - CVSSv3.1 score of 8.6
  • CVE-2026-76457 - 'Out-of-bounds read' vulnerability - CVSSv3.1 score of 8.6
  • CVE-2026-76458 - 'Improper handling of exceptional conditions' vulnerability - CVSSv3.1 score of 8.6
  • CVE-2026-76459 - 'Out-of-bounds write' vulnerability - CVSSv3.1 score of 9.8
  • CVE-2026-76471 - 'Heap-based buffer overflow' vulnerability - CVSSv3.1 score of 9.8

Remediation advice

Affected organisations are encouraged to review the Cisco advisory Cisco NX-OS Software Security Hardening Release: October 2026 (cisco-sa-hardening-nxosw1-cWzSbtR), assess exposure, and prioritise applying relevant updates.

CVE Vulnerabilities

Status Published

CVE-2026-76453

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76453 are related to improper neutralization issues that are grouped under the Common Weakness Enumeration (CWE) CWE-707.
Status Published

CVE-2026-76455

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76455 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.
Status Published

CVE-2026-76456

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76456 are related to improper input validation of special elements used in a command issue that are grouped under the Common Weakness Enumeration (CWE) CWE-20.
Status Published

CVE-2026-76457

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76457 are related to out-of-bounds read issues that are grouped under the Common Weakness Enumeration (CWE) CWE-125.
Status Published

CVE-2026-76458

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76458 are related to improper handling of exceptional conditions issues that are grouped under the Common Weakness Enumeration (CWE) CWE-703.
Status Published

CVE-2026-76459

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76459 are related to out-of-bounds write issues that are grouped under the Common Weakness Enumeration (CWE) CWE-787.
Status Published

CVE-2026-76471

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.

Last edited: 9 October 2026 11:11 am