Yokogawa FAST/TOOLS and CI Server
Summary
<p><a href="https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-176-01.json"><strong>View CSAF</strong></a></p> <h2>Summary</h2> <p><strong>Successful exploitation of this vulnerability may return a response containing the CI Server setting information.</strong></p> <p>The following versions of Yokogawa FAST/TOOLS and CI Server are affected:</p> <ul> <li>FAST/TOOLS >=R9.01|<=R10.04 </li> <li>Collaborative Information Server (CI Server) >=R1.01|<=R1.04</li> </ul> <div class="csaf-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS</th> <th>Vendor</th> <th>Equipment</th> <th>Vulnerabilities</th> </tr> </thead> <tbody> <tr> <td>v3 7.5</td> <td>Yokogawa</td> <td>Yokogawa FAST/TOOLS and CI Server</td> <td>Cleartext Transmission of Sensitive Information</td> </tr> </tbody> </table> </div> <h3>Background</h3> <ul> <li><strong>Critical Infrastructure Sectors: </strong>Critical Manufacturing, Energy, Food and Agriculture</li> <li><strong>Countries/Areas Deployed: </strong>Worldwide</li> <li><strong>Company Headquarters Location: </strong>Japan</li> </ul> <hr /> <h2>Vulnerabilities</h2> <div class="csaf-accordion"> <p><a class="csaf-accordion-toggle-all" href="https://www.cisa.gov/">Expand All +</a></p> <div class="csaf-accordion-item"> <h3><a class="csaf-accordion-toggle" href="https://www.cisa.gov/">CVE-2026-11833</a></h3> <div class="csaf-accordion-content"> <p>The web server may return a response containing the CI Server setting information. This information could be exploited by an attacker for other attacks.</p> <p><a href="https://www.cve.org/CVERecord?id=CVE-2026-11833">View CVE Details</a></p> <hr /> <h4>Affected Products</h4> <h5>Yokogawa FAST/TOOLS and CI Server</h5> <div class="ics-vendor-version-status"> <div class="ics-vendor"><strong>Vendor:</strong><br />Yokogawa</div> <div class="ics-version"><strong>Product Version:</strong><br />Yokogawa FAST/TOOLS: >=R9.01|<=R10.04, Yokogawa Collaborative Information Server (CI Server): >=R1.01|<=R1.04</div> <div class="ics-status"><strong>Product Status:</strong><br />known_affected</div> </div> <div class="ics-remediations"> <h6>Remediations</h6> <p><strong>Vendor fix</strong><br />Yokogawa recommends users update FAST/TOOLS up to R10.04 and apply patch software (R10.04 SP4).</p> <p><strong>Mitigation</strong><br />Yokogawa recommends users update Collaborative Information Server (CI Server) up to R1.05.</p> <p><strong>Mitigation</strong><br />For more information and details on implementing these mitigations, users should see the Yokogawa security advisory report YSAR-26-0004 at: <a href="https://web-material3.yokogawa.com/1/39777/files/YSAR-26-0004-E.pdf">https://web-material3.yokogawa.com/1/39777/files/YSAR-26-0004-E.pdf</a></p> <p><strong>Mitigation</strong><br />For questions related to this report, please contact the below. <br /><a href="https://contact.yokogawa.com/cs/gw?c-id=000498">https://contact.yokogawa.com/cs/gw?c-id=000498</a></p> </div> <p><strong>Relevant CWE:</strong> <a href="https://cwe.mitre.org/data/definitions/319.html">CWE-319 Cleartext Transmission of Sensitive Information</a></p> <hr /> <h4>Metrics</h4> <div class="csaf-table csaf-metrics-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS Version</th> <th>Base Score</th> <th>Base Severity</th> <th>Vector String</th> </tr> </thead> <tbody> <tr> <td>3.1</td> <td>7.5</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N">CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N</a></td> </tr> <tr> <td>4.0</td> <td>8.2</td> <td>HIGH</td> <td><a href="https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N">CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N</a></td> </tr> </tbody> </table> </div> </div> </div> </div> <hr /> <h2>Acknowledgments</h2> <ul> <li>Yokogawa reported this vulnerability to JPCERT/CC</li> </ul> <hr /> <h2>Legal Notice and Terms of Use</h2> <p>This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).</p> <hr /> <h2>Recommended Practices</h2> <p>CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.</p> <p>Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.</p> <p>Locate control system networks and remote devices behind firewalls and isolate them from business networks.</p> <p>When remote access is required, use more secure methods, such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.</p> <p>CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.</p> <p>CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.</p> <p>CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.</p> <p>Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.</p> <p>Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.</p> <p>No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.</p> <hr /> <h2>Revision History</h2> <ul> <li><strong>Initial Release Date: </strong>2026-06-25</li> </ul> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>Date</th> <th>Revision</th> <th>Summary</th> </tr> </thead> <tbody> <tr> <td>2026-06-25</td> <td>1</td> <td>Initial CISA Republication of Yokogawa Security Advisory Report YSAR-26-0004</td> </tr> </tbody> </table> <hr /> <h2>Legal Notice and Terms of Use</h2>