Cisco Expressway Series Security Hardening Release: October 2026

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Expressway Series software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses 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) to each CWE grouping. Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices. Note: Cisco may publish separate security advisories that provide additional details individual vulnerabilities that are addressed in this release. Cisco has released a software update that addresses these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: 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 21, 2026, Security Advisories .

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Expressway Series software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses 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) to each CWE grouping.

Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

Note: Cisco may publish separate security advisories that provide additional details individual vulnerabilities that are addressed in this release.

Cisco has released a software update that addresses these vulnerabilities. There are no workarounds that address these vulnerabilities.

This advisory is available at the following link:

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 21, 2026, Security Advisories .

Vulnerable Products These vulnerabilities affect Cisco Expressway-C and Cisco Expressway-E, both virtual and appliance versions, regardless of device configuration. For information which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities.

These vulnerabilities affect Cisco Expressway-C and Cisco Expressway-E, both virtual and appliance versions, regardless of device configuration.

For information which Cisco software releases are vulnerable, see the Fixed Software section of this advisory.

Products Confirmed Not Vulnerable

Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities.

The following table outlines the vulnerability classes that are addressed in this software hardening release. The CVSS score that is assigned to each CVE ID represents the maximum potential severity of the single most impactful underlying vulnerability within that specific CWE category. CVE ID Highest CVSS Score Vulnerability Class (Highest-Level CWE) Description CVE-2026-76490 8.6 CWE-787 Incorrect permission assignment for critical resources CVE-2026-76491 8.6 CWE-617 Reachable assertions CVE-2026-76492 8.6 CWE-476 Null pointer dereferences CVE-2026-76493 8.6 CWE-248 Uncaught exceptions CVE-2026-76494 7.8 CWE-94 Improper control of generation of code (code injection) CVE-2026-76495 7.8 CWE-732 Incorrect permission assignment for critical resources CVE-2026-76496 7.8 CWE-59 Improper link resolution before file access (link following) CVE-2026-76497 7.8 CWE-377 Insecure temporary files

The following table outlines the vulnerability classes that are addressed in this software hardening release. The CVSS score that is assigned to each CVE ID represents the maximum potential severity of the single most impactful underlying vulnerability within that specific CWE category.

There are no workarounds that address these vulnerabilities.

There are no workarounds that address these vulnerabilities.

To remediate these vulnerabilities and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory. Fixed Releases In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section. Cisco Expressway Series Release First Fixed Release X14 and earlier Migrate to a fixed release. X15.5.3 and earlier X15.5.20 The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

To remediate these vulnerabilities and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.

In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.

The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

Exploitation and Public Announcements

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

These vulnerabilities were found during internal security testing using existing testing processes as well as frontier AI models.

These vulnerabilities were found during internal security testing using existing testing processes as well as frontier AI models.

Cisco Security Vulnerability Policy

To learn Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy . This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco. For additional information on Cisco's vulnerability management, disclosure cadence, and software patching strategy, see Cisco's Transition to a Risk-Based Vulnerability Disclosure Model .

To learn Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy . This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

For additional information on Cisco's vulnerability management, disclosure cadence, and software patching strategy, see Cisco's Transition to a Risk-Based Vulnerability Disclosure Model .

Related to This Advisory

Version Description Section Status Date 1.0 Initial public release. - Final 2026-OCT-21 Show Less

SOFTWARE DOWNLOADS AND TECHNICAL SUPPORT The Cisco Support and Downloads page on Cisco.com provides information licensing and downloads. This page can also display customer device support coverage for customers who use the My Devices tool. Please note that customers may download only software that was procured from Cisco directly or through a Cisco authorized reseller or partner and for which the license is still valid. Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC) . Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade. When considering software upgrades , customers are advised to regularly consult the advisories for the relevant Cisco products to determine exposure and a complete upgrade solution. In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers. LEGAL DISCLAIMER DETAILS CISCO DOES NOT MAKE ANY EXPRESS OR IMPLIED GUARANTEES OR WARRANTIES OF ANY KIND, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, CISCO DOES NOT GUARANTEE THE ACCURACY OR COMPLETENESS OF THIS INFORMATION. THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. Copies or summaries of the information contained in this Security Advisory may lack important information or contain factual errors. Customers are advised to visit the Cisco Security Advisories page for the most recent version of this Security Advisory. The Cisco Product Security Incident Response Team (PSIRT) assesses only the affected and fixed release information that is documented in this advisory. See the Cisco Security Vulnerability Policy for more information.

SOFTWARE DOWNLOADS AND TECHNICAL SUPPORT

The Cisco Support and Downloads page on Cisco.com provides information licensing and downloads. This page can also display customer device support coverage for customers who use the My Devices tool. Please note that customers may download only software that was procured from Cisco directly or through a Cisco authorized reseller or partner and for which the license is still valid.

Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC) . Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

When considering software upgrades , customers are advised to regularly consult the advisories for the relevant Cisco products to determine exposure and a complete upgrade solution. In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

LEGAL DISCLAIMER DETAILS

CISCO DOES NOT MAKE ANY EXPRESS OR IMPLIED GUARANTEES OR WARRANTIES OF ANY KIND, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, CISCO DOES NOT GUARANTEE THE ACCURACY OR COMPLETENESS OF THIS INFORMATION. THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

Copies or summaries of the information contained in this Security Advisory may lack important information or contain factual errors. Customers are advised to visit the Cisco Security Advisories page for the most recent version of this Security Advisory. The Cisco Product Security Incident Response Team (PSIRT) assesses only the affected and fixed release information that is documented in this advisory. See the Cisco Security Vulnerability Policy for more information.

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