The Honeywell IQ4x building management controller, exposes its full web-based HMI without authentication in its factory-default configuration. With no user module configured, security is disabled by design and the system operates under a System Guest (level 100) context, granting read/write privileges to any party able to reach the HTTP interface. Authentication controls are only enforced after a web user is created via U.htm, which dynamically enables the user module. Because this function is accessible prior to authentication, a remote user can create a new account with administrative read/write permissions enabling the user module and imposing authentication under attacker-controlled credentials. This action can effectively lock legitimate operators out of local and web-based configuration and administration.
References
| Link | Resource |
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| https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-069-03.json | Issue Tracking |
| https://www.cisa.gov/news-events/ics-advisories/icsa-26-069-03 | Third Party Advisory US Government Resource |
| https://www.honeywell.com/us/en/contact | Product |
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
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Configuration 3 (hide)
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History
No history.
Information
Published : 2026-03-12 21:16
Updated : 2026-06-17 10:43
NVD link : CVE-2026-3611
Mitre link : CVE-2026-3611
CVE.ORG link : CVE-2026-3611
JSON object : View
Products Affected
honeywell
- iq41x
- iq4e
- iq4nc
- iq412_firmware
- iq422_firmware
- iq4e_firmware
- iq4nc_firmware
- iq412
- iq422
- iq41x_firmware
CWE
CWE-306
Missing Authentication for Critical Function
