CVE-2026-76490 - Vulnerability Details

- Cisco Expressway Series Software Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities

Description

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 software hardening releases that address multiple internally discovered vulnerabilities.  

The vulnerabilities tracked by CVE-2026-76490 are related to issues concerning out-of-bounds writes that are grouped under the Common Weakness Enumeration (CWE) Base CWE-787.

Published: 2026-10-21

Score: 8.6 High

EPSS: < 1% Very Low

KEV: No

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco TelePresence Video Communication Server (VCS) Expressway

unknown

Version	Status	Constraints
`X8.11.2`	affected	—
`X8.6`	affected	—
`X8.11.3`	affected	—
`X8.2.2`	affected	—
`X8.8.3`	affected	—
`X8.11.0`	affected	—
`X12.5.2`	affected	—
`X8.1.1`	affected	—
`X8.9`	affected	—
`X12.5.1`	affected	—
`X12.5.6`	affected	—
`X8.7.3`	affected	—
`X12.6.0`	affected	—
`X8.11.1`	affected	—
`X8.5`	affected	—
`X8.9.1`	affected	—
`X8.10.2`	affected	—
`X8.8.2`	affected	—
`X8.5.3`	affected	—
`X8.1`	affected	—
`X8.9.2`	affected	—
`X8.11.4`	affected	—
`X12.5.4`	affected	—
`X8.8.1`	affected	—
`X8.2.1`	affected	—
`X8.5.1`	affected	—
`X8.6.1`	affected	—
`X8.1.2`	affected	—
`X8.8`	affected	—
`X8.10.0`	affected	—
`X12.5.3`	affected	—
`X8.10.1`	affected	—
`X12.5.7`	affected	—
`X8.10.3`	affected	—
`X8.7.1`	affected	—
`X8.2`	affected	—
`X12.5.8`	affected	—
`X8.7`	affected	—
`X8.5.2`	affected	—
`X12.5.9`	affected	—
`X12.5.0`	affected	—
`X8.10.4`	affected	—
`X8.7.2`	affected	—
`X12.5.5`	affected	—
`X12.6.1`	affected	—
`X12.6.2`	affected	—
`X12.6.3`	affected	—
`X12.6.4`	affected	—
`X12.7.0`	affected	—
`X12.7.1`	affected	—
`X14.0.0`	affected	—
`X14.0.1`	affected	—
`X14.0.2`	affected	—
`X14.0.3`	affected	—
`X14.0.4`	affected	—
`X14.0.5`	affected	—
`X14.0.6`	affected	—
`X14.0.7`	affected	—
`X14.0.8`	affected	—
`X14.2.0`	affected	—
`X14.0.9`	affected	—
`X14.2.1`	affected	—
`X14.2.2`	affected	—
`X14.0.11`	affected	—
`X14.2.5`	affected	—
`X14.0.10`	affected	—
`X14.2.6`	affected	—
`X14.2.7`	affected	—
`X14.3.0`	affected	—
`X14.3.1`	affected	—
`X14.3.2`	affected	—
`X14.3.3`	affected	—
`X15.0.0`	affected	—
`X14.3.4`	affected	—
`X14.3.5`	affected	—
`X15.0.1`	affected	—
`X15.0.2`	affected	—
`X15.0.3`	affected	—
`X14.3.6`	affected	—
`X15.2.0`	affected	—
`X15.2.1`	affected	—
`X15.2.2`	affected	—
`X15.2.3`	affected	—
`X14.3.7`	affected	—
`X15.2.4.`	affected	—
`X15.2.4`	affected	—
`X15.3.0`	affected	—
`X15.3.1`	affected	—
`X15.3.2`	affected	—
`X15.4.0`	affected	—
`X15.5.0`	affected	—
`X15.5.1`	affected	—
`X15.5.2`	affected	—

No data.

Vendor Product Confidence Versions

Cisco

Expressway Series

100%

Version	Status	Scheme	Platform
`[X8.11.2,*]`	affected	generic	—
`[X8.6,*]`	affected	generic	—
`[X8.11.3,*]`	affected	generic	—
`[X8.2.2,*]`	affected	generic	—
`[X8.8.3,*]`	affected	generic	—
`[X8.11.0,*]`	affected	generic	—
`[X12.5.2,*]`	affected	generic	—
`[X8.1.1,*]`	affected	generic	—
`[X8.9,*]`	affected	generic	—
`[X12.5.1,*]`	affected	generic	—
`[X12.5.6,*]`	affected	generic	—
`[X8.7.3,*]`	affected	generic	—
`[X12.6.0,*]`	affected	generic	—
`[X8.11.1,*]`	affected	generic	—
`[X8.5,*]`	affected	generic	—
`[X8.9.1,*]`	affected	generic	—
`[X8.10.2,*]`	affected	generic	—
`[X8.8.2,*]`	affected	generic	—
`[X8.5.3,*]`	affected	generic	—
`[X8.1,*]`	affected	generic	—
`[X8.9.2,*]`	affected	generic	—
`[X8.11.4,*]`	affected	generic	—
`[X12.5.4,*]`	affected	generic	—
`[X8.8.1,*]`	affected	generic	—
`[X8.2.1,*]`	affected	generic	—
`[X8.5.1,*]`	affected	generic	—
`[X8.6.1,*]`	affected	generic	—
`[X8.1.2,*]`	affected	generic	—
`[X8.8,*]`	affected	generic	—
`[X8.10.0,*]`	affected	generic	—
`[X12.5.3,*]`	affected	generic	—
`[X8.10.1,*]`	affected	generic	—
`[X12.5.7,*]`	affected	generic	—
`[X8.10.3,*]`	affected	generic	—
`[X8.7.1,*]`	affected	generic	—
`[X8.2,*]`	affected	generic	—
`[X12.5.8,*]`	affected	generic	—
`[X8.7,*]`	affected	generic	—
`[X8.5.2,*]`	affected	generic	—
`[X12.5.9,*]`	affected	generic	—
`[X12.5.0,*]`	affected	generic	—
`[X8.10.4,*]`	affected	generic	—
`[X8.7.2,*]`	affected	generic	—
`[X12.5.5,*]`	affected	generic	—
`[X12.6.1,*]`	affected	generic	—
`[X12.6.2,*]`	affected	generic	—
`[X12.6.3,*]`	affected	generic	—
`[X12.6.4,*]`	affected	generic	—
`[X12.7.0,*]`	affected	generic	—
`[X12.7.1,*]`	affected	generic	—
`[X14.0.0,*]`	affected	generic	—
`[X14.0.1,*]`	affected	generic	—
`[X14.0.2,*]`	affected	generic	—
`[X14.0.3,*]`	affected	generic	—
`[X14.0.4,*]`	affected	generic	—
`[X14.0.5,*]`	affected	generic	—
`[X14.0.6,*]`	affected	generic	—
`[X14.0.7,*]`	affected	generic	—
`[X14.0.8,*]`	affected	generic	—
`[X14.2.0,*]`	affected	generic	—
`[X14.0.9,*]`	affected	generic	—
`[X14.2.1,*]`	affected	generic	—
`[X14.2.2,*]`	affected	generic	—
`[X14.0.11,*]`	affected	generic	—
`[X14.2.5,*]`	affected	generic	—
`[X14.0.10,*]`	affected	generic	—
`[X14.2.6,*]`	affected	generic	—
`[X14.2.7,*]`	affected	generic	—
`[X14.3.0,*]`	affected	generic	—
`[X14.3.1,*]`	affected	generic	—
`[X14.3.2,*]`	affected	generic	—
`[X14.3.3,*]`	affected	generic	—
`[X15.0.0,*]`	affected	generic	—
`[X14.3.4,*]`	affected	generic	—
`[X14.3.5,*]`	affected	generic	—
`[X15.0.1,*]`	affected	generic	—
`[X15.0.2,*]`	affected	generic	—
`[X15.0.3,*]`	affected	generic	—
`[X14.3.6,*]`	affected	generic	—
`[X15.2.0,*]`	affected	generic	—
`[X15.2.1,*]`	affected	generic	—
`[X15.2.2,*]`	affected	generic	—
`[X15.2.3,*]`	affected	generic	—
`[X14.3.7,*]`	affected	generic	—
`[X15.2.4.,*]`	affected	generic	—
`[X15.2.4,*]`	affected	generic	—
`[X15.3.0,*]`	affected	generic	—
`[X15.3.1,*]`	affected	generic	—
`[X15.3.2,*]`	affected	generic	—
`[X15.4.0,*]`	affected	generic	—
`[X15.5.0,*]`	affected	generic	—
`[X15.5.1,*]`	affected	generic	—
`[X15.5.2,*]`	affected	generic	—

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Remediation

No solution or workaround provided in the CVE record.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00346.

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-exwy-hardening-FhcqBVcs

History

Thu, 22 Oct 2026 15:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco expressway Series
Vendors & Products		Cisco Cisco expressway Series

Thu, 22 Oct 2026 14:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Wed, 21 Oct 2026 17:15:00 +0000

Type	Values Removed	Values Added
Description		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 software hardening releases that address multiple internally discovered vulnerabilities.   The vulnerabilities tracked by CVE-2026-76490 are related to issues concerning out-of-bounds writes that are grouped under the Common Weakness Enumeration (CWE) Base CWE-787.
Title		Cisco Expressway Series Software Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities
Weaknesses		CWE-787
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-exwy-hardening-FhcqBVcs
Metrics		cvssV3_1 `{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}`

Subscriptions

Cisco Expressway Series

MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-10-21T16:17:29.557Z

Updated: 2026-10-22T13:37:52.794Z

Reserved: 2026-08-19T12:02:03.640Z

Link: CVE-2026-76490

Vulnrichment

Updated: 2026-10-22T13:35:06.350Z

NVD

Status : Awaiting Analysis

Published: 2026-10-21T17:19:08.340

Modified: 2026-10-22T14:17:47.227

Link: CVE-2026-76490

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-10-22T14:57:19Z

Weaknesses

CWE-787
Out-of-bounds Write

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Exploitation none

Automatable yes

Technical Impact partial

Subscriptions

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