Repeated Unauthorized Access and Data Leaks: Companies Must Check These Fundamental Holes First

This article summarizes the recent unauthorized access incidents and data leaks and outlines actions companies should take, based on government and related agency publications as of October 16, 2026. JPCERT/CC, IPA, NICT, and 国家サイバー統括室 reported leakage cases since September, and multiple alerts and inspection requests were issued after October 7.

As initial points of compromise, publicly available apps, externally exposed APIs, easily guessable passwords, and access via contractors or cloud providers have been identified. NICT points out “A2B attacks,” in which attackers analyze public apps as a foothold to exploit server-side vulnerabilities; targeted weaknesses include IDOR, SSRF, RCE, and SQL injection.

Many techniques are not novel but exploit “basic holes” such as known vulnerabilities, flaws in authorization and input validation, and configuration errors. Police Agency data show that suspicious access for vulnerability exploration and similar activity increased to 13,687 attempts per day per IP in the first half of 2026 (up 50.7% year on year), indicating that scanning activity is spreading.

国家サイバー統括室 states that "fully preventing intrusion is difficult," emphasizing the importance of early detection and rapid response. The article urges management, CSIRT/SOC/IT departments, web engineers, and general employees to confirm and implement fundamental measures appropriate to their roles.

Finally, while the potential for AI to improve attackers' efficiency is noted, the article concludes that the current priority is reviewing existing basic protections and strengthening abnormality detection and incident response capabilities.