Fast\/toolsApplication · Yokogawa

CVE-2025-66606

CRITICAL · 9.6 CVSS v3.1 Published 2026-02-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. This product does not properly encode URLs. An attacker could tamper with web pages or execute malicious scripts. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a Cross-Site Scripting (XSS) vulnerability in Yokogawa FAST/TOOLS web interfaces. The product fails to properly encode URLs and user-supplied input, allowing attackers to inject malicious scripts into web pages served by the affected packages (RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB). The flaw affects versions R9.01 through R10.04.

MitigationApply output encoding to all user-controlled input and URLs within the web application; implement Content Security Policy headers; upgrade to a patched version once Yokogawa releases updates for this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Fast\/toolsApplication
Affected:>= r9.01, <= r10.04

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed FAST/TOOLS version
    Check the installed version of Yokogawa FAST/TOOLS using system information utilities, about dialogs, or version lookup files in the installation directory. Common locations include installation logs, registry entries, or version info files.
    Affected if The installed version falls within R9.01 through R10.04 inclusive
  2. Determine if web components are running
    Identify whether any FAST/TOOLS web services are active. Check for processes such as RVSVRN.exe, UNSVRN.exe, or HMIWEB services running on the system.
    Affected if Any of the affected web components (RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) are running as services or processes
  3. Check web server exposure
    Identify if the FAST/TOOLS web interfaces are accessible over the network by reviewing web server configurations, IIS/Apache settings, or listening ports (commonly ports 80/443 or custom FAST/TOOLS web ports).
    Affected if The web interface ports are open and accessible, indicating the XSS-vulnerable web pages could be served to users
  4. Verify web application is handling user input
    Review web application configuration files or monitored traffic to confirm that user-supplied input or URLs are being processed by the FAST/TOOLS web interfaces.
    Affected if The web application processes user-controlled input without output encoding, which is the condition for XSS exploitation

A defender is affected if FAST/TOOLS version R9.01 through R10.04 is installed AND the web interface components (RVSVRN, UNSVRN, HMIWEB, FTEES, or HMIMOB) are running and accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply output encoding to all user-controlled input and URLs within the web application; implement Content Security Policy headers; upgrade to a patched version once Yokogawa releases updates for this vulnerability.

Fix this in Fast\/tools Scoped from the published advisory
  • Consultation8.0 h
  • Implementation24.0 h
  • Testing16.0 h
  • Review / QA8.0 h
56.0 hours of engineering $9,760
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $15,616.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-66606 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-66606 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data