Short answer: No.


Long answer: Not at its inception or at this present time.

Antisemitism is a category of hate. Essentially a sub-category of racism in general.

Cultural Marxism is an ideological anti-conservative conspiracy theory.
A conspiracy theory can be hateful in nature. The conspiracy theory is geared towards things conservatives hate, but it is based on the thought leaders exported from a school, not a group of people.

There are a great many antisemitic people in this world in just about every group of people. An unfortunate truth. But the school, people from the school, and thought leaders were not all Jewish. Even so, being of Jewish heritage doesn't necessarily mean the person cant be antisemitic. Likewise it is possible for a specific group of Jewish people to be hated independently from Jewish people in general. 

Given that it is a conspiracy theory it is easy to tie to fringe groups or ideas. Which, when attempting to demonize it, would be easy to associate with antisemitism due to the time and location of many of the people at its origin.

However, many theories or groups can evolve over time. This can cause some concepts to become permanently associated. So it is possible for Cultural Marxism to evolve into an antisemitic form, if a branch of it isn't already there.

Edit: To clarify some points.