Cyber Resilience

CVE-2025-66596

Open Redirect in Yokogawa Fast\/Tools r9.01 – r10.04

Open Redirect
Published
09 February 2026
Modified
06 March 2026
Patch / advisory
View advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0015 5th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-66596 is a medium-severity Open Redirect (CWE-601) vulnerability in Yokogawa Fast\/Tools. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Spearphishing Link (T1566.002); ranked at the 5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-7 (Boundary Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. This product does not properly validate request headers. When an attacker inserts an invalid host header, users could be redirected to malicious sites. The affected products and versions…

more

are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

CWE(s)
CWE-601

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1566.002 Spearphishing Link Initial Access
Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems.
attack.mitre.org →
T1204.001 Malicious Link Execution
An adversary may rely upon a user clicking a malicious link in order to gain execution.
attack.mitre.org →
Why these techniques?

Open redirect via invalid Host header (CWE-601) directly enables crafted malicious links for phishing and user execution.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-66594Same product: Yokogawa Fast\/Tools
CVE-2025-66598Same product: Yokogawa Fast\/Tools
CVE-2025-66602Same product: Yokogawa Fast\/Tools
CVE-2025-66597Same product: Yokogawa Fast\/Tools
CVE-2025-66605Same product: Yokogawa Fast\/Tools
CVE-2025-66604Same product: Yokogawa Fast\/Tools
CVE-2025-66606Same product: Yokogawa Fast\/Tools
CVE-2025-66608Same product: Yokogawa Fast\/Tools
CVE-2025-66607Same product: Yokogawa Fast\/Tools
CVE-2025-66601Same product: Yokogawa Fast\/Tools

Affected Assets

yokogawa
fast\/tools
r9.01 — r10.04

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SC-7 Boundary Protection
  • SI-2 Flaw Remediation
Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires validation of all inputs including HTTP request headers to block malformed Host headers that trigger open redirects.

SC-7 Boundary Protection partial match
prevent

Boundary-protection mechanisms such as WAF rules can inspect and sanitize Host headers before they reach the vulnerable FAST/TOOLS application.

SI-2 Flaw Remediation partial match
prevent

Requires timely application of vendor patches that correct the missing Host-header validation in R9.01–R10.04.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.23 Web filtering partial match
mitigates

Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.

References