Authentication bypass using an alternate path or channel in Plat\'Home Co.,Ltd. products - CVE-2026-21411

Vulnerability identifier: #VU120981

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-21411

CWE-ID: CWE-288

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to the authentication bypass using an alternate path or channel. A remote attacker on the local network can bypass administrator authentication and change the password.

OpenBlocks IoT DX1
OpenBlocks IoT EX/BX
OpenBlocks IX9
OpenBlocks IoT VX2
OpenBlocks IDM RX1
OpenBlocks IoT FX1

Install updates from vendor's website.

OpenBlocks IoT DX1 - update to 5.0.8
OpenBlocks IoT EX/BX - update to 5.0.8
OpenBlocks IX9 - update to 5.0.8
OpenBlocks IoT VX2 - update to 5.0.8
OpenBlocks IDM RX1 - update to 5.0.8
OpenBlocks IoT FX1 - update to 5.0.8

• https://jvn.jp/en/vu/JVNVU97172240/index.html

• Authentication bypass using an alternate path or channel in Plat'Home OpenBlocks series