The Core Config Manager (CCM) in Nagios XI versions prior to CCM 3.0.8 / Nagios XI 5.7.5 contains multiple cross-site scripting (XSS) vulnerabilities in the overlay UI elements and the Notification/Check Period 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.
Conclusion & alert: CVE-2020-36861 is rated Low Risk (31/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.38%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
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 | 2026-06-27 | 0.33% | 0.38% | +0.05% |
| 2 | 2026-06-15 | 0.50% | 0.33% | -0.17% |
| 3 | 2026-05-26 | — | 0.50% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.1 | 4.0 | MEDIUM |
|
— | — | [email protected] |
| 5.4 | 3.1 | MEDIUM |
|
2.3 | 2.7 | [email protected] |
| URL | Tags |
|---|---|
| https://www.nagios.com/changelog/nagios-xi/ | Release Notes |
| https://www.vulncheck.com/advisories/nagios-xi-ccm-xss-via-overlay-rendering-and-notification-check-period-pages | Third Party Advisory |