Medium severity · published Aug 24, 2026
CVE-2026-34491
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Johnson Controls Metasys 14 and Johnson Controls Metasys 15 allows Cross Site…
6.1
CVSS
0.4%
EPSS
No
On KEV
Description
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Johnson Controls Metasys 14 and Johnson Controls Metasys 15 allows Cross Site Scripting. This issue affects Metasys 14: before 14.1.5; Metasys 15: before 15.0.1.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
M1
Metasys 14 · Johnson Controls
before 14.1.5 · source: vendor
M1
Metasys 15 · Johnson Controls
before 15.0.1 · source: vendor
In the news
VulnerabilityHigh
Johnson Controls Metasys
View CSAF Summary Successful exploitation of this vulnerability could allow a low-privilege user or attacker to inject a persistent malicious payload via a crafted URL that executes in the context of other users' sessions, including administrators, potentially leading to session hijacking and unauthorized access. The following versions of Johnson Controls Metasys are affected: Metasys 12 vers:all/* (CVE-2026-34491) Metasys 13 vers:all/* (CVE-2026-34491) Metasys 14 Metasys 15 CVSS Vendor Equipment Vulnerabilities v3 8 Johnson Controls Inc Johnson Controls Metasys Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Background Critical Infrastructure Sectors: Critical Manufacturing, Commercial Facilities, Government Services and Facilities, Transportation Systems, Energy Countries/Areas Deployed: Worldwide Company Headquarters Location: Ireland Vulnerabilities Expand All + CVE-2026-34491 A low-privilege user can inject a malicious XSS payload into the Metasys UI via a crafted URL. The payload persists across logins and executes in the browser context of other users, including administrators. View CVE Details Affected Products Johnson Controls Metasys Vendor: Johnson Controls Inc Product Version: Johnson Controls Inc Metasys 12: vers:all/*, Johnson Controls Inc Metasys 13: vers:all/*, Johnson Controls Inc Metasys 14: <v14.1.5,...
Aug 13, 2026·CISA Advisories