Cyber Resilience

CVE-2025-66596

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

Published
09 February 2026
Modified
06 March 2026
Patch / 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 39 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

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 Phishing (T1566); 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 AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

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)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-66601Same product: Yokogawa Fast\/Tools
CVE-2025-66598Same product: Yokogawa Fast\/Tools
CVE-2025-66603Same product: Yokogawa Fast\/Tools
CVE-2025-66607Same product: Yokogawa Fast\/Tools
CVE-2025-66606Same product: Yokogawa Fast\/Tools
CVE-2025-66597Same product: Yokogawa Fast\/Tools
CVE-2025-66602Same product: Yokogawa Fast\/Tools
CVE-2025-66604Same product: Yokogawa Fast\/Tools
CVE-2025-66608Same product: Yokogawa Fast\/Tools
CVE-2025-66594Same product: Yokogawa Fast\/Tools

Affected Assets

yokogawa
fast\/tools
r9.01 — r10.04

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

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

Input validation directly checks and rejects untrusted redirect targets before they are used in a response.

Information flow enforcement can restrict redirects to only approved/trusted destinations, stopping untrusted user-supplied URLs from being followed.

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.

mitigates

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

References