CVE-2025-66603: Yokogawa Electric FAST/TOOLS · CWE-358
Affects Yokogawa Electric FAST/TOOLSSource CVE Database V5
Not known to be exploited · CVSS 2.1 Low.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Yokogawa Electric CorporationFAST/TOOLS | Affected
| Fixed in– |
AI-suggested
To mitigate this vulnerability, organizations should consider the following specific actions: 1) Configure the FAST/TOOLS web server or any intermediate web servers and proxies to disable or restrict the HTTP OPTIONS method, allowing only necessary HTTP methods such as GET and POST. 2) Implement strict network segmentation and firewall rules to limit access to the FAST/TOOLS web interface to trusted hosts and networks only. 3) Monitor web server logs for unusual or unexpected HTTP OPTIONS requests that could indicate reconnaissance activity. 4) Employ web application firewalls (WAFs) capable of detecting and blocking suspicious HTTP methods or anomalous traffic patterns. 5) Maintain up-to-date inventories of Yokogawa FAST/TOOLS versions deployed and plan for timely patching once official fixes become available. 6) Conduct security awareness training for users to recognize and report suspicious activities that might involve social engineering or phishing, given the user interaction requirement. 7) Review and harden authentication and authorization mechanisms around the FAST/TOOLS web interface to reduce the risk of further exploitation.
Description
CVE-2025-66603 is a low-severity vulnerability in Yokogawa Electric Corporation's FAST/TOOLS software versions R9.01 to R10.04. The issue arises because the web server accepts the HTTP OPTIONS method, which can disclose information about supported HTTP methods. While this does not directly allow exploitation, it can aid attackers in reconnaissance and facilitate other attacks. The vulnerability does not require authentication but does require user interaction and has a high attack complexity, limiting its exploitability. There are no known exploits in the wild, and no patches have been released yet. European organizations using FAST/TOOLS in critical industrial control systems should be aware of this issue. Mitigations include restricting or disabling the OPTIONS method on the web server and monitoring for unusual HTTP requests. Countries with significant industrial automation sectors using Yokogawa products, such as Germany and the UK, may be more affected.