A personal data breach occurs when there’s a breach of security leading to the accidental or unlawful destruction, loss, alteration, unauthorized disclosure of, or access to, personal data processed. If this happens, the organization holding the personal data must notify the supervisory authority without undue delay. If the personal data breach is likely to result in a high risk to your rights and freedoms and the risk hasn’t been mitigated, then you, as an individual, must also be informed.