Vulnerability · Published Oct 30, 2025 · Assigned by VulnCheck

CVE-2023-53689Nagios Fusion < 4.2.0 License Information Reflected XSS

Medium 6.0

In plain English

A medium-severity cross-site scripting in Fusion from Nagios. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities).

Severity (CVSS 4.0)6.0Medium

Exploit odds (30 days)0.9%top 40.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Nagios Fusion versions prior to 4.2.0 contain a reflected cross-site scripting (XSS) vulnerability in the license key configuration flow that can result in execution of attacker-controlled script in the browser of a user who follows a crafted URL. While the application server itself is not directly corrupted by the reflected XSS, the resulting browser compromise can lead to credential/session theft and unauthorized administrative actions.

Affected products (as reported)

Vendor	Product	Versions
Nagios	Fusion	0 – before 4.2.0

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N

References

https://www.nagios.com/products/security/#fusion vendor-advisory, patch
https://www.nagios.com/changelog/nagios-fusion/ release-notes, patch
https://www.vulncheck.com/advisories/nagios-fusion-license-information-reflected-xss third-party-advisory