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Hard-coded CredentialsWeakness · CWE-798

CVE-2026-5667

HIGH · 7.2 CVSS v4.0 Published 2026-06-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
No privileges Zero-click

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 · unedited
Use of Hard-coded Credentials vulnerability in Mitsubishi Electric Room Air Conditioners (for Japan and outside Japan); Wireless LAN Adapters for Room Air Conditioners (for Japan and outside Japan); Wireless LAN Adapters for Packaged Air Conditioners (for Japan and outside Japan); Refrigerators (for Japan); Heat Pump Water Heaters / HEMS-Compatible Adapters / Wireless LAN Adapters (for Japan); Bathroom Dryer / Heater / Ventilation Systems (for Japan); Adapters for Airflow Ventilation Systems, Heat Pump Chilled / Hot Water Systems, and Ventilation / Air-Conditioning System Air Resorts (for Japan); Lossnay Central Ventilation Systems (for Japan); Smart Switches for Ventilation Fans and Lossnay (for Japan); IH Cooking Heaters (for Japan); and Rice Cookers (for Japan) allows an attacker within Wi-Fi radio range of an affected product to access the affected product using a hard-coded SSID and password, thereby obtaining device data such as operation status, room set temperature, and room temperature; changing the air-conditioner or Wi-Fi settings; or causing Wi-Fi communication to enter a denial-of-service (DoS) condition.

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 · high confidence

Multiple Mitsubishi Electric home appliances contain hard-coded Wi-Fi credentials (SSID and password) embedded in firmware. An attacker within Wi-Fi radio range can discover and connect to affected devices using these known credentials, then read sensitive device data (operation status, temperatures), modify settings, or cause denial-of-service.

MitigationUsers should change default Wi-Fi credentials if the device supports it, disable Wi-Fi when not needed, and implement network segmentation to isolate IoT devices. Vendor firmware updates are required to replace hard-coded credentials with unique, randomized credentials.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
Adjacent
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Inventory Mitsubishi Electric Wi-Fi appliances
    Survey your network and physical space for Mitsubishi Electric home appliances with wireless capability (smart home devices, HVAC controllers, kitchen appliances with Wi-Fi). Document each device model number and firmware version if accessible.
    Affected if Any Mitsubishi Electric Wi-Fi-enabled appliance is present in the environment
  2. Check device firmware version
    Access the device settings menu or administrative interface to retrieve the firmware version. Compare against any vendor-released version notes that address hard-coded credential fixes.
    Affected if Firmware version is older than versions that removed hard-coded credentials (or version is unknown and device has not been updated)
  3. Inspect Wi-Fi network for device SSIDs
    Use a Wi-Fi scanner tool to enumerate nearby wireless networks. Look for SSIDs that match default Mitsubishi Electric device naming patterns or unknown/unexpected networks from these devices.
    Affected if A Wi-Fi network with a default or predictable SSID associated with a Mitsubishi device is visible and responds to connection attempts
  4. Verify Wi-Fi credential configuration
    Access the device Wi-Fi setup through its mobile app or web interface. Check whether the SSID and password are still at factory default values or have been changed by the user.
    Affected if Device Wi-Fi credentials remain at factory default settings
  5. Confirm device accessibility
    Attempt to connect to the device Wi-Fi network using known default credentials (refer to product documentation for factory defaults). Check if authentication succeeds and device data is accessible.
    Affected if Connection succeeds using default credentials and device operation data or settings are readable

If you have Mitsubishi Electric Wi-Fi-enabled appliances with firmware that has not been updated to remove hard-coded credentials, and the device Wi-Fi uses default credentials, you are affected by this vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Users should change default Wi-Fi credentials if the device supports it, disable Wi-Fi when not needed, and implement network segmentation to isolate IoT devices. Vendor firmware updates are required to replace hard-coded credentials with unique, randomized credentials.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA6.0 h
42.0 hours of engineering $7,360
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-5667 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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