CRITICAL CVSS 10.0
Published: 2026-03-12

CVE-2026-3611

honeywell iq4e_firmware Security Advisory (CVE-2026-3611)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-3611 impacting honeywell iq4e_firmware. Evaluated with CVSS Base Score of 10.0 (CRITICAL).

Original NVD Description

Source: NIST NVD
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.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product honeywell / iq4e_firmware
Affected Versions *
Weakness Enumeration CWE-306

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-3611 impacting honeywell iq4e_firmware.

⚡ Nuclei Detection Template (YAML) cve-2026-3611.yaml
id: cve-2026-3611

info:
  name: honeywell iq4e_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-3611 affecting honeywell iq4e_firmware.
    Evaluation: The Honeywell IQ4x building management controller, exposes its full web-based HMI without authentication in its factory-default configuration. With no...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-3611
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 10.0
    cve-id: CVE-2026-3611
    cwe-id: CWE-306
  tags: cve,cve-2026-3611,honeywell,iq4e_firmware,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "iq4e_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-3611.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-3611
# Target: honeywell iq4e_firmware | CVSS: 10.0 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-3611 (honeywell iq4e_firmware)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against honeywell iq4e_firmware scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-3611.sh
# Recommended Remediation & Patching Commands for CVE-2026-3611
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install iq4e_firmware 2>/dev/null || \
sudo dnf upgrade iq4e_firmware 2>/dev/null || \
sudo yum update iq4e_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i iq4e_firmware 2>/dev/null || rpm -qa | grep -i iq4e_firmware

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-3611 in honeywell iq4e_firmware?

Review vendor-specific security notices and update honeywell iq4e_firmware packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-3611?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-3611?

CVE-2026-3611 is classified with a CVSS 3.1 Base Score of 10.0 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
10.0
CRITICAL SEVERITY
CVE ID CVE-2026-3611
Weakness CWE-306
Vendor honeywell
Product iq4e_firmware
Published 2026-03-12
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H