CVE-2026-21661 AC2000 Uncontrolled Search Path Element
An attacker can exploit uncontrolled search paths in Johnson Controls AC2000 to execute arbitrary code on Windows systems.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21661?
CVE-2026-21661 is a high-severity path traversal vulnerability in Johnson Controls AC2000, published on 6 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Uncontrolled Search Path Element vulnerability in JohnsonControls AC2000 on Windows allows Leveraging/Manipulating Configuration File Search Paths.
This issue affects AC2000: from 10.6 before release 10, from 11.0 before release 9, from 12 before release 3.
Weakness: CWE-427
Which versions are affected by CVE-2026-21661?
How do I fix CVE-2026-21661?
No fix has been published for CVE-2026-21661 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-21661 being exploited?
There is no known exploitation of CVE-2026-21661 in the wild and no public exploit code.
Sources
Also known as GHSA-qcgm-qmr8-52ww.