CVE-2026-3611
The Honeywell IQ4x building management controller, exposes its full web-based HMI without authentication in its factory-default configuration.
Published Mar 12, 2026 · updated Jun 17, 2026 · honeywell iq4e firmware
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.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 12, 2026 · NIST NVD
Detected
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
Jun 17, 2026 · NIST NVD
Updated
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
Affected
- cpe honeywell/iq412 firmwareversion unspecified
- cpe honeywell/iq41x firmwareversion unspecified
- cpe honeywell/iq422 firmwareversion unspecified
- cpe honeywell/iq4e firmwareversion unspecified
- cpe honeywell/iq4nc firmwareversion unspecified
Sources
- NIST NVDVulnerability recordCVE-2026-3611
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
nvd.nist.gov