Vulnerability · Published Oct 21, 2026 · Assigned by cisco

CVE-2026-76490Cisco Expressway Series Software Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities

High 8.6

In plain English

A high-severity out-of-bounds write in Cisco TelePresence Video Communication Server (VCS) Expressway from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)8.6High
Exploit odds (30 days)0.4%top 61.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
Cisco Cisco TelePresence Video Communication Server (VCS) Expressway X8.11.2X8.6X8.11.3X8.2.2X8.8.3X8.11.0X12.5.2X8.1.1

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

References