What is CVE-2025-66598?

CVE-2025-66598 is a high-severity vulnerability in Yokogawa Fast\/tools, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 7.5/10. Published 2026-02-09.

How severe is CVE-2025-66598?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Yokogawa Fast\/tools

CVE-2025-66598

A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. This product supports old SSL/TLS versions, potentially allowing an attacker to decrypt communications with the web server. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

Vulnerability class: POODLE (CVE-2014-3566)

Published 2026-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (4.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Yokogawa Fast\/tools
Yokogawa Electric Corporation Fast/tools — versions R9.01

Weakness classification (CWE)

CWE-327 — Use of a Broken or Risky Cryptographic Algorithm

References

7168b535-132a-4efe-a076-338f829b2eb9 (Vendor Advisory)

Frequently asked questions

What is CVE-2025-66598?: CVE-2025-66598 is a high-severity vulnerability in Yokogawa Fast\/tools, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 7.5/10. Published 2026-02-09.
How severe is CVE-2025-66598?: High severity. CVSS v3 base score is 7.5 out of 10.