The Maine Office of the Attorney General disclosed a data breach affecting Bishop Moore Catholic High School on January 29, 2021, stemming from an external system compromise at Blackbaud, Inc.—a third-party vendor managing the school’s data. The breach, detected on December 21, 2020, exposed sensitive personal information, specifically Social Security Numbers (SSNs), of 5,981 individuals, including students, staff, or associated parties. The incident highlights vulnerabilities in third-party data handling, as Blackbaud’s systems were exploited, leading to unauthorized access. SSNs are high-value targets for identity theft, financial fraud, and long-term exploitation, posing significant risks to affected individuals. While the school itself may not have been directly targeted, the reliance on external vendors introduced a critical security gap. The breach underscores the cascading consequences of supply-chain attacks, where a single vendor’s compromise can impact multiple organizations and thousands of individuals. No ransomware or immediate financial demands were reported, but the exposure of SSNs constitutes a severe privacy violation with potential long-term repercussions for victims.