news leak vs disclosure

news leak and disclosure both are nouns.

Word	Noun	Adjective	Verb	Adverb
news leak	Yes	No	No	No
disclosure	Yes	No	No	No

As nouns, disclosure is a hypernym of news leak; that is, disclosure is a word with a broader meaning than news leak:

news leak: unauthorized (especially deliberate) disclosure of confidential information
disclosure: the speech act of making something evident

Other hypernyms of news leak include revealing, revelation.

news leak (noun)	disclosure (noun)
unauthorized (especially deliberate) disclosure of confidential information	the speech act of making something evident