AC2000 Uncontrolled Search Path Element

published 2026-05-06 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-27865

cvss: 8.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Johnson Controls AC2000 release 3, release 9, release 10

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-26-125-05 updated 2026-05-05 cvss 8.7

Johnson Controls CEM AC2000

Johnson Controls Inc. CEM AC2000 12.0, 11.0, 10.6
affected: mitigation “Johnson Controls recommends users apply the following mitigations:” johnsoncontrols.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 6 mo ago (2026-05-06)

Exploit prediction

0.11% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
CNA	4.0	8.4	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

Johnson Controls AC2000

Classification

Weakness

CWE-427 Uncontrolled Search Path Element

References

johnsoncontrols.com /trust-center/cybersecurity/security-advisories

Sources

CVE List CVE-2026-21661
NVD CVE-2026-21661

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary