CVE-2026-48550: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Nagios Enterprises, LLC. Nagios Core
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.
AI Analysis
Technical Summary
CVE-2026-48550 is a reflected cross-site scripting vulnerability affecting Nagios Core prior to version 4.5.14 and Nagios XI prior to 2026R1.7. The issue exists in the cmd.cgi script where the NagFormId parameter is not properly neutralized during web page generation. An unauthenticated remote attacker can exploit this by sending a maliciously crafted URL to an authenticated user, causing arbitrary JavaScript execution in the victim's browser.
Potential Impact
Successful exploitation can lead to execution of arbitrary JavaScript in the context of the victim's browser session, potentially allowing session hijacking, unauthorized actions, or information disclosure within the scope of the Nagios web interface. The vulnerability requires the victim to be authenticated and to follow a malicious link.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should exercise caution with links received from untrusted sources and consider restricting access to the Nagios web interface to trusted users only.
CVE-2026-48550: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Nagios Enterprises, LLC. Nagios Core
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.
CVSS v4.0
Score 5.1medium
Affected software
Nagios Enterprises, LLC.
Nagios Core
Nagios Enterprises, LLC.
Nagios XI
pkg:github/nagiosenterprises/nagioscoreRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-48550 is a reflected cross-site scripting vulnerability affecting Nagios Core prior to version 4.5.14 and Nagios XI prior to 2026R1.7. The issue exists in the cmd.cgi script where the NagFormId parameter is not properly neutralized during web page generation. An unauthenticated remote attacker can exploit this by sending a maliciously crafted URL to an authenticated user, causing arbitrary JavaScript execution in the victim's browser.
Potential Impact
Successful exploitation can lead to execution of arbitrary JavaScript in the context of the victim's browser session, potentially allowing session hijacking, unauthorized actions, or information disclosure within the scope of the Nagios web interface. The vulnerability requires the victim to be authenticated and to follow a malicious link.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should exercise caution with links received from untrusted sources and consider restricting access to the Nagios web interface to trusted users only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-05-21T18:34:46.418Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a7ca247bf8831d539d7ad49
Added to database: 08/12/2026, 16:41:43 UTC
Last enriched: 08/12/2026, 16:57:52 UTC
Last updated: 09/26/2026, 13:47:46 UTC
Views: 57
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