The US Patent and Trademark Office (USPTO) has admitted to a second data leak that accidentally revealed the private addresses of thousands of applicants. 

US Patent and Trademark Office Reports Massive Data Leak

According to TechCrunch, the USPTO disclosed in an email sent to affected trademark applicants this week that their private domicile addresses, which can include home addresses, were inadvertently exposed in public records between August 23, 2023, and April 19, 2024.

US law requires trademark applicants to provide private addresses to prevent fraudulent filings. While these addresses were not accessible through regular searches on the USPTO website, they were included in bulk datasets intended for academic and economic research purposes, affecting approximately 14,000 applicants.

READ NEXT: UnitedHealth Admits Paying Off Hackers After 'Substantial' Patient Data Was Compromised in Change Healthcare Cyberattack 

US Patent and Trademark Office Takes Responsibility For Data Leak

The USPTO took responsibility for the data leak, attributing it to accidental exposure during a transition to a new IT system. The agency clarified that the incident was not a result of malicious activity.

After identifying the security issue, the USPTO responded by preventing access to the affected bulk data set, deleting files, applying a fix to resolve the exposure, and conducting tests before reenabling access. 

The USPTO had a similar incident last June when it inadvertently exposed some 61,000 applicants' private addresses. The agency has already informed affected individuals that the issue has been fixed.

READ MORE: Australia's Finance Department Admits Second Data Leak in 4 Months That Revealed Confidential Information