CVE-2025-66603Network attack vector

Information disclosure via accepted HTTP OPTIONS method

Published Feb 9, 2026 · Updated Feb 9, 2026

Improper HTTP method handling in Yokogawa Electric Corporation FAST/TOOLS R9.01 through R10.04 allows remote attackers to obtain server information. The embedded web server accepts HTTP OPTIONS requests rather than rejecting that method, exposing information through its response. A remote request and active user interaction are required; the disclosed consequence is limited to information useful for follow-on attacks.

CVSS severity2.1
Low
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper HTTP method handling in Yokogawa Electric Corporation FAST/TOOLS R9.01 through R10.04 allows remote attackers to obtain server information. The embedded web server accepts HTTP OPTIONS requests rather than rejecting that method, exposing information through its response. A remote request and active user interaction are required; the disclosed consequence is limited to information useful for follow-on attacks.

The record

CVE
CVE-2025-66603
Published
Feb 9, 2026
Updated
Feb 9, 2026
Vendor
Yokogawa Electric Corporation
Product
FAST/TOOLS
Classifications
CWE-358, T1595
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=R9.01 <=R10.04

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Yokogawa Electric Corporation · FAST/TOOLSversion=R9.01 <=R10.04

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1Yokogawa Electric CorporationCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
2.1Yokogawa Electric CorporationCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-358Improperly Implemented Security Check for Standard
T1595Active Scanning

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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