The
Common Core website has been updated, and no longer states that CCSS are "internationally benchmarked". Rather it now states that CCSS are "Informed by other top-performing countries to prepare all students for success in our global economy and society". The names of the countries are not provided.
The
math page describes math through grade 8, and high school math expectations are not listed.
Addressing high school expectations, R. James Milgram and Sandra Stotsky authored a paper in Sept 2013, Lowering the Bar: How Common Math Fails to Prepare Students for STEM. Milgram and Stotsky are two of the committee members who did not sign off on common core. The Common Core website lists a set of facts/myths, about which some have said each myth is a straw man.
A different set of facts/myths can be downloaded and read here. 
