Links to CoreMedia Contents like articles and channels look like this:

https://hybris-host/yacceleratorstorefront/en/cm/best-picture-contest/

The request path "/cm" is mapped to CmContentPageController on the commerce side.

If you want to change the predefined URL prefix "/cm" for CoreMedia Content Pages, you need to customize the controller mapping for CmContentPageController and link generation in Content.url.jsp, StudioPreviewUrlService#setCmContentUrlPrefix and UrlTag#buildContentUrl.