What is CVE-2025-66603?

CVE-2025-66603 is a critical-severity vulnerability in Yokogawa Fast\/tools, classified under CWE-358. CVSS score: 9.8/10. Published 2026-02-09.

How severe is CVE-2025-66603?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Yokogawa Fast\/tools

CVE-2025-66603

A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. The web server accepts the OPTIONS method. An attacker could potentially use this information to carry out other attacks. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

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

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (18.1th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

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

Weakness classification (CWE)

CWE-358

References

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

Frequently asked questions

What is CVE-2025-66603?: CVE-2025-66603 is a critical-severity vulnerability in Yokogawa Fast\/tools, classified under CWE-358. CVSS score: 9.8/10. Published 2026-02-09.
How severe is CVE-2025-66603?: Critical severity. CVSS v3 base score is 9.8 out of 10.