Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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:XSummary
CVE-2026-21659 is a high-severity Relative Path Traversal (CWE-23) vulnerability in Johnsoncontrols Frick Controls Quantum Hd Firmware. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 43% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-21659 is an unauthenticated remote code execution (RCE) and information disclosure vulnerability stemming from a local file inclusion (LFI) flaw, tracked under CWE-23 and CWE-22. It affects Johnson Controls Frick Controls Quantum HD devices, specifically version 10.22 and prior. 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 due to its network accessibility, low complexity, and lack of prerequisites.
An unauthenticated attacker can exploit this LFI vulnerability remotely over the network to execute arbitrary code on the affected device, resulting in full system compromise. This also enables information disclosure, allowing access to sensitive data on the target system.
Mitigation details are outlined in advisories from CISA (ICSA-26-057-01) and Johnson Controls' trust center cybersecurity security advisories, available at the respective reference URLs. Security practitioners should consult these for patching instructions and workarounds applicable to Frick Controls Quantum HD devices.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9019
Vulnerability Data
Unauthenticated Remote Code Execution and Information Disclosure due to Local File Inclusion (LFI) vulnerability in Johnson Controls Frick Controls Quantum HD allow an unauthenticated attacker to execute arbitrary code on the affected device, leading to full system compromise. This issue…
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affects Frick Controls Quantum HD: Frick Controls Quantum HD version 10.22 and prior.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Explicit validation of path inputs stops .. sequences from ever being interpreted by the file system.
Information-flow rules can be configured to reject traversals that would move data outside an approved directory boundary.
Least privilege reduces the set of reachable files even when a traversal succeeds.
Secure-engineering principles require safe pathname construction and input neutralization before any file operation.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require input validation and path sanitization that prevent relative traversal.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis, but does not itself implement the fix.
Secure development lifecycle mandates input validation and path-handling controls that directly prevent relative path traversal.
Application security requirements explicitly call for controls against path traversal and other injection flaws.
Secure architecture principles include directory isolation and canonicalization, reducing but not eliminating traversal risk.
Secure coding standards require neutralizing path traversal sequences, directly addressing CWE-23.
Information access restriction limits which files can be reached, mitigating impact but not preventing the traversal flaw.