šuškati

1. (of paper, leaves) to rustle
   Neko stalno šuška kesom u bioskopu. — Someone keeps rustling a bag in the cinema.
   Lišće šuška pod nogama. — The leaves rustle underfoot.
2. colloq. (šuška se da…) to be rumored
   Šuška se da direktor odlazi. — Rumor has it the director is leaving.
   Po gradu se šuška o njihovom razvodu. — There are rumors around town about their divorce.
3. to whisper
   Šta vas dve stalno šuškate u uglu? — What are you two always whispering about in the corner?
4. (of speech) to lisp
   Mali malo šuška, ali logoped kaže da će proći. — The little one lisps a bit, but the speech therapist says it will pass.

The impersonal šuška se da… is a very common way to say "rumor has it".