Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module (QJ71E71-100 / QJ71E71-B2 / QJ71E71-B5) — Default Password
Default username and password for the Mitsubishi Electric MELSEC-Q Series Ethernet Interface Module (QJ71E71-100 / QJ71E71-B2 / QJ71E71-B5): (blank) / (blank). Learn how to log in and how to change the default credentials.
Mitsubishi Electric MELSEC-Q series Ethernet modules do not implement authentication on the Modbus/TCP interface (TCP port 502) or the dedicated MELSEC Communication Protocol port by default. Any reachable host can read/write PLC data registers without credentials. CISA advisory ICSA-16-336-03 documents unauthenticated access; a follow-up advisory ICSA-19-141-02 covered the Q-series Ethernet module as well.
| Username | Password | Access | Notes |
|---|---|---|---|
(blank / none) | (blank / none) | API | No authentication on Modbus TCP (port 502) and MELSEC protocol by default — ICSA-16-336-03 |
Responsible use
This database lists publicly documented default credentials so administrators can find and change them. Only use these on systems you own or are authorized to test.
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USER/USERFTP∅/∅Consoleadmin/∅Web UIadmin/∅Web UIadmin/wagoWeb UIadmin/adminWeb UI