Improper input validation in Nagios Fusion 4.1.8 and earlier allows a remote attacker with control over a fused server to inject arbitrary HTML, aka XSS.
Conclusion & alert: CVE-2020-28903 is rated High Exploit Risk (67.6/100): CVSS Medium severity, with high exploitation likelihood (EPSS 15.76%, 95th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
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 | 26.32% | 15.76% | -10.56% |
| 2 | 2026-04-14 | 24.86% | 26.32% | +1.46% |
| 3 | 2026-03-09 | — | 24.86% | — |
Full EPSS history (23 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.1 | 3.1 | MEDIUM |
|
2.8 | 2.7 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| URL | Tags |
|---|---|
| http://packetstormsecurity.com/files/162783/Nagios-XI-Fusion-Privilege-Escalation-Cross-Site-Scripting-Code-Execution.html | Third Party Advisory VDB Entry |
| https://skylightcyber.com/2021/05/20/13-nagios-vulnerabilities-7-will-shock-you/ | Exploit Third Party Advisory |
| https://www.nagios.com/downloads/nagios-xi/change-log/ | Release Notes Vendor Advisory |