XSS in Nagios Xi

CVE-2021-47690

The Core Config Manager (CCM) in Nagios XI versions prior to CCM 3.1.1 / Nagios XI 5.8.2 contains multiple cross-site scripting (XSS) vulnerabilities in Overlay modals. 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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (30.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47690: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47690?
CVE-2021-47690 is a medium-severity vulnerability in Nagios Xi, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-10-30.
How severe is CVE-2021-47690?
Medium severity. CVSS v3 base score is 5.4 out of 10.