CVE-2026-21656
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedImproper Control of Generation of Code ('Code Injection') vulnerability in Johnson Controls Frick Controls Quantum HD allows Code Injection. Insufficient validation of input in certain parameters may permit unexpected actions, which could impact the security of the device before authentication occurs.This issue affects Frick Controls Quantum HD version 10.22 and prior.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA code injection vulnerability in Johnson Controls Frick Controls Quantum HD version 10.22 and prior allows unauthenticated remote attackers to inject malicious code through insufficiently validated input parameters. The flaw exists in certain parameters before the authentication process, potentially enabling remote code execution on the affected industrial control device.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 10.22CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm the device modelInventory your industrial control systems and identify any Johnson Controls Frick Controls Quantum HD refrigeration controllers in your environmentAffected if The device is a Johnson Controls Frick Controls Quantum HD unit
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Check the installed firmware versionAccess the device management interface or use the vendor-supplied diagnostics tool to retrieve the current firmware version numberAffected if The firmware version is 10.22 or lower
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Verify network exposure of management interfaceReview firewall rules and network segmentation to determine if the device management ports (HTTP/HTTPS typically used for web interface) are accessible from untrusted networksAffected if Management interface is reachable from outside the isolated OT network without filtering
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Identify exposed attack surfaceScan the network for open ports on the Quantum HD device, focusing on web-based management ports that accept user inputAffected if Web management ports are exposed and accept unauthenticated input
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Review access logs for suspicious requestsExamine device or upstream firewall logs for unusual parameter patterns in HTTP requests that could indicate injection attemptsAffected if Log entries show unexpected characters or parameter tampering in requests to the device
You are affected if you have a Johnson Controls Frick Controls Quantum HD device running firmware version 10.22 or lower with its management interface network-accessible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to a patched version of Frick Controls Quantum HD once available; until then, isolate the device on a restricted network segment, implement strict firewall rules, and monitor for indicators of compromise. Given the pre-authentication nature and critical severity, treat this as a high-priority remediation.
Contact Johnson Controls/Frick Controls for the fixed firmware version (versions after 10.22)
- 1. Contact Johnson Controls or Frick Controls technical support to obtain the specific fixed firmware version for Quantum HD.
- 2. Request the latest firmware version that addresses CVE-2026-21656.
- 3. Review all upgrade documentation and release notes for the Quantum HD device.
- 4. Schedule a maintenance window for the firmware upgrade.
- 5. Back up current device configuration before performing the upgrade.
- 6. Follow the vendor's official firmware update procedure to apply the fixed version.
- 7. After upgrading, verify the device is functioning correctly and the vulnerability is resolved.
- 8. Check vendor security advisories for any additional required actions or known issues.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation12.0 h
- Testing16.0 h
- Review / QA8.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-21656 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21656 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data