The Meltdown and Spectre vulnerabilities affect pretty much anything with a chip in it.
Operating system developers including Microsoft, Apple, and the Linux Group are preparing patches – the roll out of these patches might effect also existing OPC COM/DCOM scenarios.
An update to Windows 10 (KB4056892) may cause COM/DCOM applications to stop working. This could affect any OPC user with OPC Classic applications running on Windows 10.
Microsoft has released another patch that resolves the issues.
Details of the problem and resolution can be found on the forum (link: https://opcfoundation.org/forum/classic-opc-da-ae-hda-xml-da-etc/problems-after-windows-update/