CVE-2026-34491: Improper neutralization of input during web page generation ('cross-site scripting') in Johnson Controls Metasys 14

This vulnerability involves improper neutralization of input during web page generation in Johnson Controls Metasys 14 and 15, leading to cross-site scripting (CWE-79). Specifically, versions prior to 14.1.5 for Metasys 14 and prior to 15.0.1 for Metasys 15 are affected. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required but user interaction needed, and high impact on confidentiality, integrity, and availability. The vulnerability is publicly known but no active exploitation has been reported.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected web application, potentially leading to unauthorized actions or data exposure. The impact is rated medium, reflecting the potential for significant but not critical compromise of confidentiality, integrity, and availability.

A fix is available in Johnson Controls Metasys 14.1.5 and Metasys 15.0.1. Users should upgrade to these versions or later to remediate the vulnerability. No vendor advisory content was provided, so check the vendor's official resources for detailed patch instructions and confirmation.