CVE-2026-48548
Received Received - Intake

Cross-Site Request Forgery in Nagios Core

Publication date: 2026-08-26

Last updated on: 2026-08-26

Assigner: VulnCheck

Description
Nagios Core before 4.5.12 contains a cross-site request forgery vulnerability in cmd.cgi where the CSRF protection mechanism passes validation when the NagFormId cookie is absent. Attackers can craft a malicious cross-site POST request to execute arbitrary Nagios commands as a currently authenticated user without their knowledge or consent.

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Meta Information

Published
2026-08-26
Last Modified
2026-08-26
Generated
2026-09-16
AI Q&A
2026-08-26
EPSS Evaluated
2026-09-14
NVD
CVE-2026-48548
EUVD
EUVD-2026-66598

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
nagios nagios_core to 4.5.12 (exc)
nagios nagios_core to 4.5.14 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-352 The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.

Attack-Flow Graph

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Executive Summary

Nagios Core before version 4.5.12 has a CSRF vulnerability in cmd.cgi. The CSRF protection fails when the NagFormId cookie is missing, allowing attackers to send malicious POST requests. These requests can execute arbitrary Nagios commands as an authenticated user without their knowledge or consent.

Detection Guidance

To detect this vulnerability, check if your Nagios Core version is before 4.5.12. Run the command: nagios -v /usr/local/nagios/etc/nagios.cfg to verify the version. Also inspect cmd.cgi for CSRF protection bypass attempts by monitoring POST requests without the NagFormId cookie.

Impact Analysis

An attacker could trick a logged-in Nagios user into clicking a malicious link or visiting a crafted webpage. This could lead to unauthorized execution of Nagios commands, potentially disrupting monitoring, altering configurations, or causing data breaches.

Compliance Impact

This vulnerability could lead to unauthorized access or modifications in Nagios, potentially violating GDPR (data integrity, access controls) or HIPAA (system integrity, audit controls). Unauthorized command execution may result in non-compliance with security and privacy requirements.

Mitigation Strategies

Upgrade Nagios Core to version 4.5.12 or later immediately. If upgrading is not possible, apply the official patch from Nagios Enterprises. Disable cmd.cgi access if not required or restrict it to trusted IPs.

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