CVE-2026-48550

MEDIUM 6.1

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

CVSS Score

6.1

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-79
Vendor	nagios enterprises, llc.
Product	nagios core
Published	Aug 12, 2026
Last Updated	Aug 12, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

Nagios Enterprises, LLC. / Nagios Core

0 < 4.5.14

Nagios Enterprises, LLC. / Nagios XI

0 < 2026R1.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗

nagios.com: https://www.nagios.com/security-disclosures/nagios-core/ github.com: https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog vulncheck.com: https://www.vulncheck.com/advisories/nagios-core-xi-cmd-cgi-reflected-xss-via-nagformid-parameter

Credits

Zach Hanley of Horizon3.ai