# CVE-2026-21659: Path traversal in Frick Controls Quantum HD

> Unauthenticated attackers can execute arbitrary code and read sensitive data via Local File Inclusion in Johnson Controls Frick Quantum HD devices.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Feb 2026
- **Updated:** 6 Mar 2026
- **Also known as:** GHSA-7qxc-43wm-v793

## What is CVE-2026-21659?

CVE-2026-21659 is a high-severity path traversal vulnerability in Johnson Controls Frick Controls Quantum HD, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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 affects Frick Controls Quantum HD: Frick Controls Quantum HD version 10.22 and prior.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), CWE-23 (Relative Path Traversal)

## Which versions are affected by CVE-2026-21659?

It affects 1 product.


Products: Johnsoncontrols Frick Controls Quantum Hd Firmware.

## How do I fix CVE-2026-21659?

No fix has been published for CVE-2026-21659 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21659 being exploited?

There is no known exploitation of CVE-2026-21659 in the wild and no public exploit code.

## Other vulnerabilities in Johnson Controls Frick Controls Quantum HD

- [CVE-2026-21654](https://insights.sbomify.com/CVE-2026-21654/): Johnson Controls -Frick Quantum HD- Unauthenticated Remote Code Execution (high 8.8)
- [CVE-2026-21656](https://insights.sbomify.com/CVE-2026-21656/): Johnson Controls -Frick Quantum HD- Unauthenticated Remote Code Execution (high 8.8)
- [CVE-2026-21657](https://insights.sbomify.com/CVE-2026-21657/): Johnson Controls -Frick Quantum HD- Unauthenticated Remote Code Execution (high 8.8)
- [CVE-2026-21658](https://insights.sbomify.com/CVE-2026-21658/): Johnson Controls -Frick Quantum HD- Unauthenticated Remote Code Execution (high 8.8)
- [CVE-2026-21660](https://insights.sbomify.com/CVE-2026-21660/): Johnson Controls-Frick Quantum HD-Hardcoded Email Credentials Saved as Plaintext in Firmware (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21659 and fix it if it is affected.

What it is: CVE-2026-21659 is a high-severity path traversal vulnerability in Johnson Controls Frick Controls Quantum HD, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-21659 in the wild and no public exploit code.

Affected product: Johnson Controls Frick Controls Quantum HD. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-21659/ (Markdown: https://insights.sbomify.com/CVE-2026-21659/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21659
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21659
- OSV: https://osv.dev/vulnerability/CVE-2026-21659

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-21659/
Summaries are generated and may contain mistakes; the official description above is the record.