Cisco NX-OS Software Security Hardening Release: October 2026

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class — Common Weakness Enumeration (CWE) — and assigned a single Common Vulnerabilities and Exposures identifier (CVE ID). Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-nxosw1-cWzSbtR Security Impact Rating: Critical CVE: CVE-2026-76453,CVE-2026-76455,CVE-2026-76456,CVE-2026-76457,CVE-2026-76458,CVE-2026-76459

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-2026-76453, CVE-2026-76455, CVE-2026-76456, CVE-2026-76457, CVE-2026-76458, CVE-2026-76459

Affected versions

Cisco NX-OS Software 8.2: 12 versions, from 8.2(5) to 8.2(11)
Cisco NX-OS Software 7.3: 18 versions, from 7.3(5)D1(1) to 7.3(18)N1(1)
Cisco NX-OS Software 8.4: 22 versions, from 8.4(2) to 8.4(13)
Cisco NX-OS Software 9.2: 8 versions, from 9.2(3) to 9.2(1a)
Cisco NX-OS Software 9.3: 22 versions, from 9.3(2) to 9.3(17)
Cisco NX-OS Software 8.1: 5 versions, from 8.1(1) to 8.1(1a)
Cisco NX-OS Software 8.3: 8.3(2); 8.3(1)
Cisco NX-OS Software 8.5: 8.5(1)
Cisco NX-OS Software 10.3: 20 versions, from 10.3(1) to 10.3(9)
Cisco NX-OS Software 9.4: 9 versions, from 9.4(1) to 9.4(5)
Cisco NX-OS Software 10.4: 8 versions, from 10.4(1) to 10.4(7)
Cisco NX-OS Software 10.5: 11 versions, from 10.5(1) to 10.5(5)
Cisco NX-OS Software 10.6: 9 versions, from 10.6(1) to 10.6(3s)
Cisco NX-OS System Software in ACI Mode 15.2: 25 versions, from 15.2(1g) to 15.2(8i)
Cisco NX-OS System Software in ACI Mode 16.0: 20 versions, from 16.0(1g) to 16.0(9f)
Cisco NX-OS System Software in ACI Mode 15.3: 7 versions, from 15.3(1d) to 15.3(2f)
Cisco NX-OS System Software in ACI Mode 16.1: 7 versions, from 16.1(1f) to 16.1(5e)
Cisco NX-OS System Software in ACI Mode 16.2: 16.2(1g); 16.2(2e)
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)
Cisco Unified Computing System (Managed) 6.0: 9 versions, from 6.0(1b) to 6.0(2d) (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 7, 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.