CVE-2026-48550

Nagios Core / XI cmd.cgi Reflected XSS via NagFormId Parameter

State: Published
Severity: 5.1 Medium
Published: Aug 12, 2026
Updated: Aug 14, 2026
Reserved: May 21, 2026

Description

Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to reflected cross-site scripting in cmd.cgi via the NagFormId parameter. An unauthenticated remote attacker can craft a malicious link that, when followed by an authenticated user, executes arbitrary JavaScript in the victim's browser.

Scores

CVSS	Score	Vector	Source
4.0	5.1 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N	VulnCheck
3.1	6.1 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N	VulnCheck

Weaknesses

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected Products

Product	Versions
Nagios CoreNagios Enterprises, LLC.	before 4.5.14Affected
Nagios XINagios Enterprises, LLC.	before 2026R1.7Affected

References

Security Disclosuresvendor-advisorypatch
Changelogrelease-notes
https://www.vulncheck.com/advisories/nagios-core-xi-cmd-cgi-reflected-xss-via-nagformid-parameterthird-party-advisory

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