Summary
Successful exploitation of this vulnerability may return a response containing the CI Server setting information.
The following versions of Yokogawa FAST/TOOLS and CI Server are affected:
- FAST/TOOLS >=R9.01|<=R10.04
- Collaborative Information Server (CI Server) >=R1.01|<=R1.04
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 7.5 | Yokogawa | Yokogawa FAST/TOOLS and CI Server | Cleartext Transmission of Sensitive Information |
Background
- Critical Infrastructure Sectors: Critical Manufacturing, Energy, Food and Agriculture
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: Japan
Vulnerabilities
CVE-2026-11833
The web server may return a response containing the CI Server setting information. This information could be exploited by an attacker for other attacks.
Affected Products
Yokogawa FAST/TOOLS and CI Server
Yokogawa
Yokogawa FAST/TOOLS: >=R9.01|<=R10.04, Yokogawa Collaborative Information Server (CI Server): >=R1.01|<=R1.04
known_affected
Remediations
Vendor fix
Yokogawa recommends users update FAST/TOOLS up to R10.04 and apply patch software (R10.04 SP4).
Mitigation
Yokogawa recommends users update Collaborative Information Server (CI Server) up to R1.05.
Mitigation
For more information and details on implementing these mitigations, users should see the Yokogawa security advisory report YSAR-26-0004 at: https://web-material3.yokogawa.com/1/39777/files/YSAR-26-0004-E.pdf
Mitigation
For questions related to this report, please contact the below.
https://contact.yokogawa.com/cs/gw?c-id=000498
Relevant CWE: CWE-319 Cleartext Transmission of Sensitive Information
Metrics
| CVSS Version | Base Score | Base Severity | Vector String |
|---|---|---|---|
| 3.1 | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| 4.0 | 8.2 | HIGH | 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 |
Acknowledgments
- Yokogawa reported this vulnerability to JPCERT/CC
Legal Notice and Terms of Use
This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).
Recommended Practices
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.
Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
Locate control system networks and remote devices behind firewalls and isolate them from business networks.
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.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
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.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
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.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time.
Revision History
- Initial Release Date: 2026-06-25
| Date | Revision | Summary |
|---|---|---|
| 2026-06-25 | 1 | Initial CISA Republication of Yokogawa Security Advisory Report YSAR-26-0004 |