How to Fix CVE-2026-21660: Frick Controls Quantum HD (Bundle Sibling)
By Sai Kiran Pandrala. Last verified: 2026-05-25.
CVE-2026-21660 is a sibling vulnerability in the same vendor advisory as CVE-2026-21654. Apply the same patched build and you close both. The technical detail below is what differs.
| Severity | 6.9 (Medium) |
|---|---|
| Actively exploited? | No public listing in CISA KEV |
| Affected | Frick Controls Quantum HD Frick Controls Quantum HD version 10.22 and prior |
| Fixed in | Same patched build as CVE-2026-21654 |
| Type (CWE) | CWE-256: Plaintext Storage of a Password |
What's different about CVE-2026-21660?
Hardcoded Email Credentials Saved as Plaintext in Firmware (CWE-256: Plaintext Storage of a Password) vulnerability in Frick Controls Quantum HD version 10.22 and prior lead to unauthorized access, exposure of sensitive information, and potential misuse or system compromise
This issue affects Frick Controls Quantum HD version 10.22 and prior.
How to fix CVE-2026-21660
Apply the patched build per the primary write-up: How to Fix CVE-2026-21654. All commands, verification steps, and rollback notes for Frick Controls Quantum HD are listed there.
Frequently asked questions
Does the CVE-2026-21654 patch close CVE-2026-21660?
Yes. Both CVEs are addressed by the same vendor patch. Applying the patched build closes the full bundle.
Is CVE-2026-21660 listed in CISA KEV?
No public KEV listing at the time of this writing.
Where is the official advisory?
See https://www.cisa.gov/news-events/ics-advisories/icsa-26-057-01
References
- Official vendor advisory: https://www.cisa.gov/news-events/ics-advisories/icsa-26-057-01
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21660
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary: How to Fix CVE-2026-21654
*Written by Sai Kiran Pandrala. Part of the Frick Controls Quantum HD bundle. Full procedure at how-to-fix-cve-2026-21654.*