Spillage of classified information
Spillage of classified information is a contamination of lower level systems with material of a higher classification.
The formal definition by the US Government is found in as: "Security incident that results in the transfer of classified or CUI information onto an information system not accredited (i.e., authorized) for the appropriate security level."
- CNSSI No. 4009 "National Information Assurance (IA) Glossary", Page 70, 26 April 2010