Nagios XI 5.5.6 allows reflected cross site scripting from remote unauthenticated attackers via the host parameter in api_tool.php.

published 2018-11-14 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-7582

cvss: 6.1; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 48.6%; EPSS 48.6% chance of exploitation in 30 days, percentile 98%
public exploits: 0; none known

Exploit prediction

48.55% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

tenable.com https://www.tenable.com/security/research/tra-2018-37 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.0	6.1	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

Nagios Nagios XI

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

tenable.com /security/research/tra-2018-37
exploit, third-party-advisory

Sources

CVE List CVE-2018-15712
NVD CVE-2018-15712

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary