VulnerabilityPublished 9 Feb 2026

CVE-2025-66594: Yokogawa Electric FAST/TOOLS · Generation of Error Message Containing Sensitive Information

Affects Yokogawa Electric FAST/TOOLSSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Yokogawa Electric CorporationFAST/TOOLS	Affected ≥ R9.01, ≤ R10.04	Fixed in–

AI-suggested

Limit the detail of error messages exposed to end users by configuring FAST/TOOLS to display generic error responses instead of detailed diagnostic information.
Monitor network traffic and logs for unusual access patterns or repeated error page requests that could indicate reconnaissance attempts.
Implement strict network segmentation to isolate FAST/TOOLS systems from general enterprise networks and restrict access to authorized personnel only.
Apply vendor patches or updates as soon as they become available, and maintain close communication with Yokogawa for security advisories.
Conduct regular security assessments and penetration testing focused on error handling and information leakage in industrial control systems.
Use web application firewalls (WAFs) or intrusion detection/prevention systems (IDS/IPS) to detect and block attempts to exploit error message disclosures.
Train operational technology (OT) and IT staff on the risks associated with information disclosure vulnerabilities and best practices for secure error handling.

Description

CVE-2025-66594 is a medium-severity vulnerability in Yokogawa Electric Corporation's FAST/TOOLS software versions R9.01 to R10.04. The flaw involves detailed error messages that expose sensitive information, which attackers could leverage to facilitate further attacks. The vulnerability requires no authentication or user interaction and can be exploited remotely over the network. Although no known exploits are currently in the wild, the information disclosure risk could aid attackers in reconnaissance or crafting targeted attacks. European organizations using FAST/TOOLS in critical industrial control systems may face increased risk, particularly in countries with significant industrial automation sectors. Mitigation involves restricting error message detail exposure, applying vendor patches when available, and implementing network segmentation and monitoring. Countries like Germany, France, Italy, and the UK are likely most affected due to their industrial base and usage of such control systems.

Impact

For European organizations, especially those operating critical infrastructure and industrial control systems, this vulnerability poses a risk of information leakage that could facilitate further attacks. FAST/TOOLS is widely used in process automation and control environments, including energy, manufacturing, and utilities sectors. Disclosure of sensitive error information can aid attackers in mapping system architecture, identifying software versions, or discovering configuration details, which can be used to craft targeted exploits or conduct reconnaissance for more damaging attacks. Although the vulnerability does not directly compromise confidentiality, integrity, or availability, the indirect impact through enabling subsequent attacks could be significant. European countries with large industrial bases and advanced manufacturing sectors—such as Germany, France, Italy, and the UK—are particularly at risk. The vulnerability could also affect organizations involved in energy production and distribution, where Yokogawa products are often deployed. The lack of known exploits reduces immediate risk but does not eliminate the potential for future exploitation.

Summary

CVE-2025-66594 is a vulnerability classified under CWE-209, which pertains to the generation of error messages containing sensitive information. This issue affects Yokogawa Electric Corporation's FAST/TOOLS software, specifically versions from R9.01 through R10.04, including packages RVSVRN, UNSVRN, HMIWEB, FTEES, and HMIMOB. The vulnerability arises because the software displays detailed error messages that reveal sensitive internal information on error pages. Such information disclosure can provide attackers with insights into system configurations, software versions, or other data that can be leveraged to mount more sophisticated attacks, such as targeted exploitation or privilege escalation. The CVSS 4.0 base score is 6.9, indicating a medium severity level. The vector indicates the vulnerability is remotely exploitable over the network (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and does not affect confidentiality, integrity, or availability directly (VC:L, VI:N, VA:N). The vulnerability does not require authentication and can be exploited without user interaction, increasing its risk profile. No patches are currently linked, and no known exploits are reported in the wild, but the exposure of sensitive information in error messages is a recognized security risk, especially in industrial control systems where FAST/TOOLS is used for monitoring and control. The vulnerability was reserved in December 2025 and published in February 2026.

CWE-209Generation of Error Message Containing Sensitive Information (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product generates an error message that includes sensitive information about its environment, users, or associated data.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
Implementation
Handle exceptions internally and do not display errors containing potentially sensitive information to a user.
Implementation · Attack Surface Reduction
Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Fuzzing for application mapping (opens in a new tab)
Padding Oracle Crypto Attack (opens in a new tab)
Query System for Information (opens in a new tab)
Blind SQL Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

web-material3.yokogawa.com/1/39206/files/YSAR-26-0001-E.pdf (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Feb 2026, 13:17 UTC

WeaknessesCWE-209

Technical details

References

Community reviews

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