CVE-2026-34491

Johnson Controls Inc Metasys 12 — kwetsbaarheid 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 Scripting. This issue affects Metasys 14: before 14.1.5; Metasys 15: before 15.0.1.

CVSS 8.0No patch available

This record: live connection— last retrieved: 24 September 2026 at 05:12.

Vendor

Johnson Controls Inc.

Product

Metasys 12

up to version vers:all/*

Published

24 August 2026

Last modified

3 September 2026

Original source information

Taken directly from NVD, CISA or the vendor — sometimes in English, unchanged from the source.

Technical description

CVSS 3.1 — vector details

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Attack vector

NETWORK

Privileges required

NONE

User interaction

NONE

Confidentiality

None

Integrity

None

Availability

None

EPSS — Exploit Prediction Scoring System

Probability of exploitation within 30 days

0.3%

Percentile

22e

Source: FIRST.org, updated on 23 September 2026.

Patch information

Johnson Controls recommends the following actions:

IACS Radar assessment

Our own interpretation and context for the source data above.

IACS Radar assessment

Our own interpretation and context for this vulnerability — not an official source.

IACS Radar priority score

42/ 100

Based on CVSS 8.0, EPSS 0.3%, industrial relevance 40/100.

Combines CVSS, EPSS, KEV status, industrial relevance and exposure relevance — a complement to, not a replacement for, the individual scores below and above.

Conditions for exploitation

•Network access to the affected device or segment is required.
•No valid credentials are needed.
•No user interaction required.

Operational impact & energy relevance

Limited impact on availability; the risk lies mainly with confidentiality or integrity of process data.

No strong energy-sector-specific signals recognised; general OT/ICS relevance.

Recommended defensive measures

•Apply the latest firmware or software update and validate its integrity.
•Restrict network access to the affected device to a dedicated OT management segment.
•Implement network segmentation in line with zones and conduits (IEC 62443-3-2).
•Monitor for abnormal protocol traffic using an OT-aware detection system.

Industrial relevance score

40/ 100

• Mentioned in an official CISA ICS advisory, which confirms direct relevance to industrial control systems.
• Sector indication recognised in the description: energieopwekking.

Classification is provisional; manual verification by an OT security analyst is recommended.

Classified by IACS Radar-analysepijplijn (geautomatiseerd) on 24 September 2026.

IEC 62443 mapping

IEC 62443-4-1FR3 · Systeemintegriteit

Automatic IACS Radar assessment based on the reported CWE weakness classification; not an official certification statement.

Loading vulnerabilities…