Cisco TelePresence Video Communication Server Expressway assertion

Summaryinfo

A vulnerability identified as critical has been detected in Cisco TelePresence Video Communication Server Expressway. Affected by this issue is some unknown functionality. This manipulation causes assertion. The identification of this vulnerability is CVE-2026-76491. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Cisco TelePresence Video Communication Server Expressway. Affected by this vulnerability is some unknown functionality. The manipulation with an unknown input leads to a assertion vulnerability. The CWE definition for the vulnerability is CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. As an impact it is known to affect availability. The summary by CVE is:

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-2026-76491 are related to issues concerning reachable assertions that are grouped under the Common Weakness Enumeration (CWE) Base CWE-617.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-76491 since 08/19/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/21/2026).

Upgrading eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Unified Communication Software

Vendor

• Cisco

Name

• TelePresence Video Communication Server Expressway

Version

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

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion