# CVE-2025-66523: Reflected Cross-Site Scripting (XSS) Vulnerability in na1.foxitesign.foxit.com via Unsanitized URL Parameters

> Attackers can inject arbitrary scripts via unsanitized URL parameters, potentially compromising authenticated user sessions on Foxit eSign.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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:** 20 Jan 2026
- **Updated:** 20 Jan 2026
- **Also known as:** GHSA-jv72-wxjv-h5q2

## What is CVE-2025-66523?

CVE-2025-66523 is a medium-severity cross-site scripting vulnerability in na1.foxitesign.foxit.com, published on 20 Jan 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

URL parameters are directly embedded into JavaScript code or HTML attributes without proper encoding or sanitization. This allows attackers to inject arbitrary scripts when an authenticated user visits a crafted link.

This issue affects na1.foxitesign.foxit.com: before 2026‑01‑16.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-66523?

It affects 1 product.


Products: Foxit Esign.

## How do I fix CVE-2025-66523?

No fix has been published for CVE-2025-66523 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66523 being exploited?

There is no known exploitation of CVE-2025-66523 in the wild and no public exploit code.

## Other vulnerabilities in na1.foxitesign.foxit.com

- [CVE-2026-4947](https://insights.sbomify.com/CVE-2026-4947/): Insecure Direct Object Reference (IDOR) Leading to Signature Forgery in Foxit eSign (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66523 and fix it if it is affected.

What it is: CVE-2025-66523 is a medium-severity cross-site scripting vulnerability in na1.foxitesign.foxit.com, published on 20 Jan 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-2025-66523 in the wild and no public exploit code.

Affected product: na1.foxitesign.foxit.com. 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-2025-66523/ (Markdown: https://insights.sbomify.com/CVE-2025-66523/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66523
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66523
- OSV: https://osv.dev/vulnerability/CVE-2025-66523

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66523/
Summaries are generated and may contain mistakes; the official description above is the record.