breach of security
From Longman Dictionary of Contemporary Englishbreach of securitybreach of securityFAILan action in which someone manages to learn secret information or manages to get into a place that is guarded There had been a major breach of security at the airbase. → breachExamples from the Corpusbreach of security• Who was responsible for the breach of security that alerted the garrison at Benghazi has never been established.