According to the New York Times

The report says that the US plans to cancel thousands of visas of Chinese graduate students and researchers in the US who have direct ties to universities affiliated with the People's Liberation Army, citing US officials familiar with discussions.

Despite recent escalation in tensions between the two countries, the sources say that plans to cancel Chinese student visas were under consideration even before the Hong Kong national security law was announced by Chinese officials.

Adding that the plan would be the first designed to bar the access of a category of Chinese students in the country, with the possibility of further educational restrictions.

The report also adds that:

"Officials acknowledged there was no direct evidence that pointed wrongdoing by the students who are about to lose their visas. Instead, suspicions by American officials center on the Chinese universities at which students trained as undergraduates."

The full report can be found here (may be gated).