HP LaserJet M4555, M525, and M725; LaserJet flow MFP M525c; LaserJet Enterprise color flow MFP M575c; Color LaserJet CM4540, M575, and M775; and ScanJet Enterprise 8500fn1 FutureSmart devices do not properly encrypt PDF documents, which allows remote attackers to obtain sensitive information via unspecified vectors.
https://h20564.www2.hp.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c03888014