Mitsubishi Electric MELSOFT Update Manager (Update B)

An attacker with local access and low-level user privileges could execute arbitrary code with elevated permissions on the MELSOFT Update Manager, potentially compromising connected industrial control systems or causing process interruptions.

Organizations using Mitsubishi Electric industrial control systems should prioritize this fix. The MELSOFT Update Manager is used by control system engineers and OT staff to deploy firmware updates to PLCs, drives, and other industrial devices. Utilities, manufacturers, and any facility running Mitsubishi-based automation are affected. The vulnerability impacts the engineering workstations and servers where updates are staged before deployment to the plant floor.

An attacker with local access to a machine running MELSOFT Update Manager could exploit integer underflow or improper restriction of rendered UI layers to execute arbitrary commands. This could happen if the attacker gains access to an engineering workstation, laptop, or server where the Update Manager is installed, or through a malicious file loaded during the update process.