# CVE-2017-20209: Nagios Fusion versions prior to 4.0.1 are vulnerable to cross-site scripting (XSS) via the Users and Servers pages…

Source: https://junglewise.ai/threats/cve-2017-20209-nagios-fusion-versions-prior-to-4-0-1-are-vulnerable-to-cross  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-10-30  
License: CC BY 4.0 with a link back

CVE-2017-20209 · Severity: medium · CVSS 6.1 · Published 2025-10-30

Nagios Fusion versions prior to 4.0.1 are vulnerable to cross-site scripting (XSS) via the Users and Servers pages. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

Technologies: [Nagios Fusion](https://junglewise.ai/threats/technologies/nagios-fusion). Vendors: [Nagios](https://junglewise.ai/threats/vendors/nagios).

## Quick answers

**Is CVE-2017-20209 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2017-20209 being exploited in the wild.

**How severe is CVE-2017-20209?** Medium severity, with a CVSS score of 6.1, published 30 October 2025.

**Which products and versions are affected?** Nagios Fusion. The advisory does not name versions.

**Is there a fix for CVE-2017-20209?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2017-20209?** Check whether you run Nagios Fusion. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Nagios Fusion

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