Cisco TelePresence Video Communication Server Expressway out-of-bounds write

Summaryinfo

A vulnerability categorized as critical has been discovered in Cisco TelePresence Video Communication Server Expressway. Affected by this vulnerability is an unknown functionality. The manipulation results in out-of-bounds write. This vulnerability was named CVE-2026-76490. The attack may be performed from remote. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Cisco TelePresence Video Communication Server Expressway. Affected is an unknown functionality. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability is traded as CVE-2026-76490 since 08/19/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/21/2026).

Upgrading eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

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

License

• commercial

Website

• Vendor: https://www.cisco.com/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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