CVE-2026-48549
Received Received - Intake

CSRF Bypass in Nagios Core and Nagios XI

Publication date: 2026-08-26

Last updated on: 2026-08-26

Assigner: VulnCheck

Description
Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 contains a CSRF vulnerability in cmd.cgi. When no Cookie header is present, the double-submit cookie protection can be bypassed by supplying matching NagFormId and nagFormId values in the POST body, allowing a cross-site request to execute Nagios commands as a currently authenticated user.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-26
Last Modified
2026-08-26
Generated
2026-08-26
AI Q&A
2026-08-26
EPSS Evaluated
N/A
NVD
CVE-2026-48549
EUVD
EUVD-2026-66599

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
nagios nagios_core to 4.5.13 (exc)
nagios nagios_xi to 2026R1.5 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
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

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a Cross-Site Request Forgery (CSRF) vulnerability in Nagios Core before 4.5.13 and Nagios XI before 2026R1.5. It affects the cmd.cgi component and allows bypassing double-submit cookie protection by supplying matching NagFormId and nagFormId values in the POST body when no Cookie header is present. This enables attackers to execute Nagios commands as an authenticated user.

Detection Guidance

To detect this vulnerability, check Nagios Core versions before 4.5.13 and Nagios XI versions before 2026R1.5. Verify if cmd.cgi is accessible without proper CSRF protections. Inspect POST requests to cmd.cgi for mismatched or missing NagFormId and nagFormId parameters.

Impact Analysis

An attacker could trick an authenticated user into executing malicious Nagios commands without their knowledge. This could lead to unauthorized changes in Nagios configurations, service disruptions, or command execution on the Nagios server.

Mitigation Strategies

Upgrade Nagios Core to version 4.5.13 or later and Nagios XI to version 2026R1.5 or later. Ensure double-submit cookie protection is properly enforced. Review and restrict access to cmd.cgi to authenticated users only.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-48549. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart