# CVE-2025-66606: Cross-site scripting in FAST/TOOLS

> Attackers can execute malicious scripts or tamper with web pages in Yokogawa FAST/TOOLS due to improper URL encoding.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Feb 2026
- **Updated:** 9 Feb 2026
- **Also known as:** GHSA-gx8g-pw4x-wmmv

## What is CVE-2025-66606?

CVE-2025-66606 is a low-severity cross-site scripting vulnerability in Yokogawa Electric Corporation FAST/TOOLS, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

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

This product does not
properly encode URLs. An attacker could tamper with web pages or execute
malicious scripts.

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

Weakness: CWE-86 (Improper Neutralization of Invalid Characters in Identifiers in Web Pages)

## Which versions are affected by CVE-2025-66606?

It affects 1 product.


Products: Yokogawa Fast\/Tools.

## How do I fix CVE-2025-66606?

No fix has been published for CVE-2025-66606 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66606 being exploited?

There is no known exploitation of CVE-2025-66606 in the wild and no public exploit code.

## Other vulnerabilities in Yokogawa Electric Corporation FAST/TOOLS

- [CVE-2025-66597](https://insights.sbomify.com/CVE-2025-66597/): Weak cryptography in FAST/TOOLS (high 8.8)
- [CVE-2025-66608](https://insights.sbomify.com/CVE-2025-66608/): Path traversal in FAST/TOOLS (high 8.7)
- [CVE-2025-66598](https://insights.sbomify.com/CVE-2025-66598/): Weak cryptography in FAST/TOOLS (high 7.1)
- [CVE-2025-66594](https://insights.sbomify.com/CVE-2025-66594/): Information disclosure in FAST/TOOLS (medium 6.9)
- [CVE-2025-66596](https://insights.sbomify.com/CVE-2025-66596/): Open redirect in FAST/TOOLS (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66606 and fix it if it is affected.

What it is: CVE-2025-66606 is a low-severity cross-site scripting vulnerability in Yokogawa Electric Corporation FAST/TOOLS, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-66606 in the wild and no public exploit code.

Affected product: Yokogawa Electric Corporation FAST/TOOLS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-66606/ (Markdown: https://insights.sbomify.com/CVE-2025-66606/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66606
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66606
- OSV: https://osv.dev/vulnerability/CVE-2025-66606

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66606/
Summaries are generated and may contain mistakes; the official description above is the record.