Cybersecurity

Nikkei Discloses Third Data Breach in a Month

Japanese media conglomerate Nikkei Inc. has reported its third cybersecurity incident in roughly a month, revealing that unauthorized access to a development system exposed 1.83 million personal information records.

Radwan AbdulhadiEditor and technology writer

Published: October 20, 2026 · Updated: October 20, 2026 · 3 min read

Nikkei Discloses Third Data Breach in a Month — Image: BleepingComputer

Third Security Incident in a Month

Japanese business news and financial information giant Nikkei Inc. has disclosed a new data breach that exposed 1.83 million personal information records. According to reporting by BleepingComputer, this marks the third cybersecurity incident the company has revealed in about a month.

Nikkei operates as a major Japanese business-focused media company and owns the Financial Times. The firm employs over 10,100 people and reports an annual revenue of $2.5 billion ( ¥393.8 billion ).

Details of the Cloud Development System Breach

Based on a public notice published by Nikkei late last week, hackers utilized stolen credentials to gain unauthorized access to a development system within the company network during the early morning hours of October 7. The intrusion exposed personal information stored by the organization in the cloud.

The company stated that subsets of the exposed data contained personally identifiable information and other sensitive details, though the majority of the records contained no identifying information. Specifically, 150,000 records included at least one of the following data types: full names, email addresses, physical addresses, telephone numbers, and dates of birth. Email addresses alone appeared in 120,000 records. Meanwhile, the remaining 1.68 million records held no identifiers, and Nikkei confirmed that no credit card information was exposed during the incident.

Company Response and Containment Efforts

Following the discovery of the unauthorized access, Nikkei revoked the abused credentials and officially notified the Personal Information Protection Commission on October 11. The firm is currently examining the full scope of the breach.

As of October 16, Nikkei noted that it had found no evidence indicating the accessed information was misused or leaked online. Furthermore, the company reported no signs of system compromise or data tampering resulting from the incident, and experienced no service disruptions or outages. Affected individuals are slated to receive individual notifications from the organization.

Addressing the ongoing security situation, Nikkei stated: “We are working urgently to establish the extent of the damage and determine the cause, and will implement the necessary measures to strengthen security.”

Prior Security Incidents at Nikkei

This event represents the third security disclosure by Nikkei in recent weeks. Earlier in the month, the organization revealed a separate breach occurring in late July when hackers compromised an employee's Google Workspace account to access personal information belonging to employees and business partners.

Additionally, in September, Nikkei reported that threat actors hijacked another employee’s Microsoft 365 account, using it to send spear-phishing emails to members of the firm’s staff.