By Roshan Fernandez

MainStreet Bancshares said a third-party vendor's compromised system led to a data security breach involving what it described as a small subset of its customers.

The company said in March it learned that the outside vendor's system had been compromised, but quickly determined the affect was unlikely to be significant, according to a filing with the Securities and Exchange Commission on Friday.

A review concluded that the vendor's system included personally identifiable information on about 4.7% of MainStreet's customers, the company said. The vendor was not identified.

A company review found that its own systems and networks had not been compromised or affected, and no unauthorized transactions had been executed.

MainStreet said affected customers were notified and provided tools to monitor any suspicious activity on May 26.

The incident did not have a material impact on MainStreet Bancshares' operations, and the company said it ceased all activity with the vendor.

Write to Roshan Fernandez at roshan.fernandez@wsj.com

(END) Dow Jones Newswires

May 30, 2025 17:47 ET (21:47 GMT)

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