Detections
Analytics
Johnson Controls Metasys 12.x / 13.x / 14.x < 14.1.5 / 15.x < 15.0.1 Cross-Site Scripting (CVE-2026-34491)
high Tenable OT Security Plugin ID 505941
Synopsis
The remote OT asset is affected by a vulnerability.Description
A low-privilege user can inject a malicious XSS payload into the Johnson Controls Metasys UI via a crafted URL. The payload persists across logins and executes in the browser context of other users, including administrators.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 vulnerability was introduced at Metasys version 12; Metasys 11 and prior are not affected, and Metasys 16.0 was fixed prior to release.
This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.
Solution
The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.Upgrade to Metasys version 16.0 or apply the latest available patch for your version (15.0.1 or 14.1.5 when available). Metasys 12 and Metasys 13 are end of support; update to a later version.
For more detailed mitigation instructions, please see Johnson Controls Product Security Advisory JCI-PSA-2026-11.
See Also
https://tyco.widen.net/s/fq5rrvnwx2/jci-psa-2026-11
https://www.cisa.gov/news-events/ics-advisories/icsa-26-225-14
https://www.johnsoncontrols.com/cyber-solutions/security-advisories
Plugin Details
Severity: High
ID: 505941
File Name: tenable_ot_johnsoncontrols_CVE-2026-34491.nasl
Version: 1.2
Type: Remote
Family: Tenable.ot
Published: 8/24/2026
Updated: 8/26/2026
Supported Sensors: Tenable OT Security
Risk Information
VPR
Risk Factor: Low
Score: 2.3
Percentile: 9.76
CVSS v3
Risk Factor: High
Base Score: 8.7
Temporal Score: 7.6
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS v4
Risk Factor: High
Base Score: 8.6
Threat Score: 6.1
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Vulnerability Information
CPE: cpe:/o:johnsoncontrols:nae55_firmware, cpe:/o:johnsoncontrols:nae85_firmware, cpe:/o:johnsoncontrols:nie55_firmware, cpe:/o:johnsoncontrols:nie59_firmware, cpe:/o:johnsoncontrols:nie85_firmware
Required KB Items: Tenable.ot/JohnsonControls
Exploit Ease: No known exploits are available
Patch Publication Date: 3/25/2026
Vulnerability Publication Date: 8/13/2026
Reference Information
CVE: CVE-2026-34491