Nagios Fusion versions prior to 4.2.0 contain a stored cross-site scripting (XSS) vulnerability in the LDAP/AD authentication-server configuration. Unsanitized user input can be stored and later rendered in the administrative UI, causing JavaScript to execute in the browser of any user who views the affected page. An attacker who can add authentication servers via LDAP/AD integration could persist a malicious payload that executes in the context of other users' browsers.
Conclusion & alert: CVE-2023-53690 is rated Moderate Risk (52.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.23%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-26 | 0.91% | 1.23% | +0.32% |
| 2 | 2026-04-09 | 0.61% | 0.91% | +0.30% |
| 3 | 2026-03-28 | — | 0.61% | — |
Full EPSS history (10 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.2 | 4.0 | MEDIUM |
|
— | — | [email protected] |
| 4.8 | 3.1 | MEDIUM |
|
1.7 | 2.7 | [email protected] |
| URL | Tags |
|---|---|
| https://www.nagios.com/changelog/nagios-fusion/ | Release Notes |
| https://www.nagios.com/products/security/#fusion | Vendor Advisory |
| https://www.vulncheck.com/advisories/nagios-fusion-ldap-ad-integration-stored-xss | Third Party Advisory |