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PatchSiren cyber security CVE debrief

CVE-2025-66607 Yokogawa CVE debrief

CVE-2025-66607 affects Yokogawa FAST/TOOLS and is described by CISA as an insecure response-header setting that could let an attacker redirect users to malicious sites. The supplied CVSS 3.1 vector rates it low severity with network access and higher attack conditions required, and only integrity impact indicated. Yokogawa’s remediation guidance is to update to R10.04, apply patch software CS_e12787, and then apply R10.04 SP3.

Vendor
Yokogawa
Product
FAST/TOOLS
CVSS
LOW 3.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-02-10
Original CVE updated
2026-02-10
Advisory published
2026-02-10
Advisory updated
2026-02-10

Who should care

OT and ICS administrators, Yokogawa FAST/TOOLS operators, SCADA platform owners, and security teams responsible for user access to FAST/TOOLS environments.

Technical summary

The advisory describes a response-header configuration weakness in FAST/TOOLS. Based on the supplied CVSS vector (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N), exploitation is network-reachable but not simple, with no privilege requirements and no user interaction required in the score, and the primary impact is limited to integrity. The record does not indicate confidentiality or availability impact.

Defensive priority

Low to moderate. The score is low, but the issue can affect user trust and route users toward malicious destinations, so it should be handled in routine OT patching and configuration review.

Recommended defensive actions

  • Update Yokogawa FAST/TOOLS to revision R10.04.
  • Apply Yokogawa patch software CS_e12787.
  • After patching, move to R10.04 SP3 as recommended by Yokogawa.
  • Review FAST/TOOLS response-header behavior and related redirect handling during validation.
  • Follow CISA ICS recommended practices for patching, hardening, zoning, and defense-in-depth around OT systems.

Evidence notes

This debrief is based on the supplied CISA CSAF advisory ICSA-26-041-01 and its remediation text. The record provided no KEV listing and no ransomware-campaign association. Timing follows the supplied published and modified dates of 2026-02-10.

Official resources

CISA published the advisory on 2026-02-10 as ICSA-26-041-01, republishing YSAR-26-0001-E. The supplied enrichment indicates no KEV listing and no ransomware-campaign use.