CVE-2026-34491 Cross-site scripting in Metasys 14
Cross-site scripting in Johnson Controls Metasys allows attackers to inject malicious scripts, potentially compromising user sessions and data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-34491?
CVE-2026-34491 is a medium-severity cross-site scripting vulnerability in Johnson Controls Metasys 14, published on 24 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-34491?
How do I fix CVE-2026-34491?
No fix has been published for CVE-2026-34491 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-34491 being exploited?
There is no known exploitation of CVE-2026-34491 in the wild and no public exploit code.
Sources
Also known as GHSA-2fj7-6j2c-3972.