Cyber Posture

CVE-2026-21654

Critical

Published: 27 February 2026

Published
27 February 2026
Modified
02 March 2026
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0015 35.6th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in Johnson Controls Frick Controls Quantum HD allows OS Command Injection. Insufficient validation of input in certain parameters may permit unexpected actions, which could impact the…

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security of the device before authentication occurs.This issue affects Frick Controls Quantum HD version 10.22 and prior.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates OS command injection by enforcing validation of untrusted inputs used in OS commands before processing.

prevent

Addresses the specific flaw in Quantum HD version 10.22 and prior through timely installation of vendor-provided security patches.

prevent

Complements input validation by restricting the types and quantities of inputs to prevent exploitation of command injection parameters.

Security SummaryAI

CVE-2026-21654 is an OS Command Injection vulnerability (CWE-78) affecting Johnson Controls Frick Controls Quantum HD in versions 10.22 and prior. The flaw stems from improper neutralization of special elements used in OS commands, with insufficient validation of input in certain parameters. This allows unexpected actions that impact device security even before authentication occurs. The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.

Remote attackers require no privileges, authentication, or user interaction to exploit the issue over the network with low complexity. Successful exploitation enables arbitrary OS command execution on the affected device, potentially resulting in high-impact compromise of confidentiality, integrity, and availability, such as full system control or disruption of industrial control functions.

CISA has published ICS Advisory ICSA-26-057-01, and Johnson Controls has issued related guidance via its Trust Center cybersecurity security advisories page, detailing mitigation steps for this vulnerability.

Details

CWE(s)

Affected Products

johnsoncontrols
frick controls quantum hd firmware
≤ 10.22

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
Why these techniques?

Unauthenticated remote OS command injection in a network-accessible device enables exploitation of public-facing application (T1190) and arbitrary command execution via OS command interpreter (T1059).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References