Nagios Core / XI CSRF via cmd.cgi Double-Submit Cookie
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.
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.
Nagios Core / XI Authenticated RCE via Unfiltered NOTIFICATION-Family Macro Substitution
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to authenticated remote code execution via unfiltered NOTIFICATION-family macro substitution through the com_data parameter. When a notification command references $NOTIFICATIONCOMMENT$ or $NOTIFICATIONAUTHOR$ in a shell-reachable position, authenticated UI users can run arbitrary commands as the nagios user. Exploitation requires a non-default configuration in which a notification command references these macros in a shell-executed command line.
Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to authenticated remote code execution via custom-variable macro injection through the Nagios Remote Data Processor (NRDP). When a custom variable defined on a host, service, or contact is referenced in a shell-executed command line, an authenticated attacker with NRDP access can inject OS commands through the macro value. Exploitation requires a non-default configuration in which a custom variable is defined and referenced in a shell-executed command.
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to DOM-based cross-site scripting in jsonquery.js. Unencoded JSON string values reflected from stored fields are inserted into the DOM without sanitization, allowing attackers to run arbitrary JavaScript in the victim's browser.
Nagios Core / XI CSRF Protection Bypass via Double-Submit Cookie
Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 contain a cross-site request forgery protection bypass via a self-supplied double-submit cookie. An attacker can supply matching cookie and request parameter values to bypass CSRF protection, enabling unauthenticated attackers to run commands as authorized users via malicious links.
Nagios Core / XI cmd.cgi Reflected XSS via NagFormId Parameter
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.
Nagios Core application version 4.2.4 is vulnerable to Site-Wide Cross-Site Request Forgery (CSRF) in many functions, like adding – deleting for hosts or servers.
Nagios 4.4.5 allows an attacker, who already has administrative access to change the "URL for JSON CGIs" configuration setting, to modify the Alert Histogram and Trends code via crafted versions of the archivejson.cgi, objectjson.cgi, and statusjson.cgi files. NOTE: this vulnerability has been mistakenly associated with CVE-2020-1408.
Nagios Core 4.4.2 has XSS via the alert summary reports of plugin results, as demonstrated by a SCRIPT element delivered by a modified check_load plugin to NRPE.
Medium · CVSS 5.5EPSS 4.45%Public exploitFix available
CVE-2018-13458
qh_core in Nagios Core 4.4.1 and earlier is prone to a NULL pointer dereference vulnerability, which allows attackers to cause a local denial-of-service condition by sending a crafted payload to the listening UNIX socket.
Medium · CVSS 5.5EPSS 4.45%Public exploitFix available
CVE-2018-13457
qh_echo in Nagios Core 4.4.1 and earlier is prone to a NULL pointer dereference vulnerability, which allows attackers to cause a local denial-of-service condition by sending a crafted payload to the listening UNIX socket.
Medium · CVSS 5.5EPSS 1.34%Public exploitFix available
CVE-2018-13441
qh_help in Nagios Core version 4.4.1 and earlier is prone to a NULL pointer dereference vulnerability, which allows attacker to cause a local denial-of-service condition by sending a crafted payload to the listening UNIX socket.