Critical Vulnerability in Yokogawa FAST/TOOLS and CI Server Exposes Sensitive Information
In June 2026, a critical vulnerability (CVE-2026-11833) was identified in Yokogawa's FAST/TOOLS and Collaborative Information Server (CI Server). The web server component of these systems could return HTTP responses containing sensitive configuration information without requiring authentication. This flaw, present in FAST/TOOLS versions R9.01 through R10.04 and CI Server versions R1.01 through R1.04, exposes system settings that attackers could exploit for further attacks. The vulnerability has been assigned a CVSS 4.0 score of 8.2, indicating high severity. This incident underscores the ongoing risks associated with cleartext transmission of sensitive information in industrial control systems. Organizations utilizing these Yokogawa products should prioritize applying the recommended updates to mitigate potential exploitation and enhance their cybersecurity posture.
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