Disclosure of secret information (7)
(Other definitions for leakage that I've seen before include "Gradual escape" , "Escape of liquid - or private information" , "Amount seeping away" , "Liquid/gas accidentally lost" , "Escape of liquid/gas" .)
(Other definitions for leak that I've seen before include "Reveal (secret)" , "Unauthorised disclosure of confidential information" , "Accidental hole that allows fluid to escape" , "Spill secrets" , "Seep; disclose" .)