KEPServerEX v6.0 to v6.9, ThingWorx Kepware Server v6.8 and v6.9, ThingWorx Industrial Connectivity (all versions), OPC-Aggregator (all versions), Rockwell Automation KEPServer Enterprise, GE Digital Industrial Gateway Server v7.68.804 and v7.66, and Software Toolbox TOP Server all 6.x versions, are vulnerable to a heap-based buffer overflow. Opening a specifically crafted OPC UA message could allow an attacker to crash the server and potentially leak data.