Keio University Shonan Fujisawa Campus Email Appliance Suspected of Zero-Day Attack, Directory Server Personal Data Potentially Exposed

According to Security NEXT, Keio University detected anomalous communications originating from a spam quarantine server at its Shonan Fujisawa Campus in late November 2025 ^[1]. Following a joint investigation with Cisco, the university determined on December 18 that a software vulnerability in the appliance was highly likely exploited in a zero-day attack, and discovered on December 22 that personal data on a directory server may have been exposed ^[1]. Potentially leaked data includes names, email addresses, student or faculty ID numbers, hashed login passwords, plaintext email passwords, and encrypted Wi-Fi passwords ^[1].

Industries mainly affected: Education

Potentially leaked data includes names, email addresses, student or faculty ID numbers, hashed login passwords, plaintext email passwords, and encrypted Wi-Fi passwords ^[1].