CVE-2025-66597
Published: 09 February 2026
Summary
CVE-2025-66597 is a high-severity Use of a Broken or Risky Cryptographic Algorithm (CWE-327) vulnerability in Yokogawa Fast\/Tools. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 5.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Contacts with security groups provide timely information on broken or risky cryptographic algorithms, reducing the likelihood of their selection and use.
Ongoing education and sharing of recommended practices helps organizations identify and migrate away from broken or risky cryptographic algorithms.
Cross-organization threat feeds commonly include advances in cryptanalysis and active exploits against weak or broken algorithms, allowing organizations to deprecate them proactively.
Capital planning and funding allow selection and ongoing support of strong cryptographic algorithms rather than weak or broken ones.
Risk updates surface newly-broken or risky cryptographic algorithms as threat intelligence and computing advances evolve, enabling timely replacement.
Scanners flag use of broken or weak cryptographic algorithms via known-vulnerability databases.
Enforces approved cryptographic algorithms for each use case, blocking use of broken or risky algorithms.
Flaw remediation replaces broken or risky cryptographic algorithms once safer implementations are released by vendors.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Weak crypto (CWE-327) directly enables effective network sniffing to obtain plaintext from web server traffic.
NVD Description
A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation. This product supports weak cryptographic algorithms, potentially allowing an attacker to decrypt communications with the web server. The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN,…
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UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04
Deeper analysisAI
CVE-2025-66597 affects FAST/TOOLS software provided by Yokogawa Electric Corporation, specifically the packages RVSVRN, UNSVRN, HMIWEB, FTEES, and HMIMOB in versions R9.01 to R10.04. The vulnerability involves the use of weak cryptographic algorithms (CWE-327), which could allow an attacker to decrypt communications with the web server. It carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating high confidentiality impact with no integrity or availability effects.
An unauthenticated attacker with network access to the affected system can exploit this vulnerability with low attack complexity and without requiring user interaction. Exploitation enables the attacker to decrypt sensitive communications exchanged with the web server, potentially exposing confidential data.
Yokogawa Electric Corporation has published security advisory YSAR-26-0001-E at https://web-material3.yokogawa.com/1/39206/files/YSAR-26-0001-E.pdf, which provides further details on the vulnerability. Security practitioners should consult this advisory for recommended mitigations or patches.
Details
- CWE(s)