CVE-2025-66596 Open redirect in FAST/TOOLS

Medium 6.9 Published 9 Feb 2026 Updated 9 Feb 2026

Attackers can redirect users to malicious sites via invalid host headers in Yokogawa FAST/TOOLS industrial control software.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-66596?

CVE-2025-66596 is a medium-severity vulnerability in Yokogawa Electric Corporation FAST/TOOLS, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability has been found in FAST/TOOLS provided by Yokogawa Electric Corporation.

This product does not properly validate request headers. When an attacker inserts an invalid host header, users could be redirected to malicious sites.

The affected products and versions are as follows: FAST/TOOLS (Packages: RVSVRN, UNSVRN, HMIWEB, FTEES, HMIMOB) R9.01 to R10.04

Weakness: CWE-601

Which versions are affected by CVE-2025-66596?

It affects 1 product.

Products include Yokogawa Fast\/Tools.

How do I fix CVE-2025-66596?

No fix has been published for CVE-2025-66596 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-66596 being exploited?

There is no known exploitation of CVE-2025-66596 in the wild and no public exploit code.

Sources

Also known as GHSA-jf8c-97vf-m8j5.