VulnerabilityPublished 9 Feb 2026

CVE-2025-66608: Yokogawa Electric FAST/TOOLS · CWE-29

Affects Yokogawa Electric FAST/TOOLSSource CVE Database V5

Not known to be exploited · CVSS 8.7 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 38% 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:H/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: High
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: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
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

Monitor Yokogawa Electric Corporation communications closely and apply official patches or updates as soon as they become available for FAST/TOOLS versions R9.01 to R10.04.
Immediately restrict network access to the FAST/TOOLS web server interfaces by implementing strict firewall rules, allowing only trusted IP addresses and internal networks.
Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious URL patterns and malformed requests targeting URL validation weaknesses.
Conduct thorough audits of FAST/TOOLS deployments to identify exposed web interfaces and ensure they are not accessible from untrusted networks, including the internet.
Implement network segmentation to isolate industrial control systems from corporate and external networks, minimizing attack surface.
Enhance logging and monitoring to detect anomalous access patterns or file access attempts on FAST/TOOLS web servers.
Educate operational technology (OT) and security teams about this vulnerability to ensure rapid incident response capability.
Consider temporary disabling or limiting non-essential web server functionalities within FAST/TOOLS until patches are applied.

Description

CVE-2025-66608 is a high-severity vulnerability in Yokogawa Electric Corporation's FAST/TOOLS software versions R9.01 to R10.04. The flaw stems from improper URL validation, allowing an unauthenticated attacker to send specially crafted requests to the web server and steal files. This vulnerability does not require user interaction or privileges, making it remotely exploitable over the network. The CVSS 4.0 base score is 8.7, indicating a significant risk to confidentiality without impacting integrity or availability. No known exploits are currently reported in the wild. European organizations using FAST/TOOLS in critical industrial control or SCADA environments could face data breaches and operational risks.

Impact

For European organizations, especially those operating critical infrastructure and industrial control systems, this vulnerability poses a significant risk of confidential data leakage. Exposure of configuration files or credentials could facilitate further attacks, including unauthorized control or disruption of industrial processes. The confidentiality breach could lead to intellectual property theft, regulatory non-compliance, and reputational damage. Given the critical role of FAST/TOOLS in sectors such as energy, manufacturing, and utilities, exploitation could indirectly affect operational stability and safety. The remote, unauthenticated nature of the exploit increases the likelihood of attacks originating from external threat actors, including cybercriminals and nation-state groups. Organizations lacking network segmentation or adequate perimeter defenses are particularly vulnerable. The absence of known exploits currently provides a window for proactive mitigation, but the high severity score demands urgent attention.

CWE-29Path Traversal: '\..\filename' (opens in a new tab)
Variant weakness
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '\..\filename' (leading backslash dot dot) sequences that can resolve to a location that is outside of that directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP ASVS 4.0.3
V12.3.1 (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, 13:22 UTC

WeaknessesCWE-29

Technical details

References

Community reviews

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