Nagios XI < 2026R2 OS Command Injection via mibs.php

Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character-substitution filter that omits semicolons, pipes, and non-space IFS whitespace characters before passing them to a grep command run via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user.

An issue was discovered in Nagios XI before 5.9.3. The is_insecure_login_authenticated function uses a insecure timing comparison that leads to an attacker being able to bruteforce the admin password, by measuring timing differences in the comparison.

Open Redirect Vulnerability in Nagios XI Twilio AJAX Handler

An issue was discovered in twilio_ajax_handler.php in Nagios XI before 5.9.3. An attacker can force a user to visit a malicious site by using a open redirect vulnerability.

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.

An issue with the Autodiscover component in Nagios XI 2024R1.01 allows a remote attacker to escalate privileges via a crafted Dashlet.

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 / XI DOM-based XSS via jsonquery.js

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 XI < 2024R1.3.2 Authenticated Arbitrary File Upload Path Traversal RCE

Nagios XI < 2024R1.3.2 contains a remote code execution vulnerability by chaining two flaws: an arbitrary file upload and a path traversal in the Core Config Snapshots interface. The issue arises from insufficient validation of file paths and extensions during MIB upload and snapshot rename operations. Exploitation results in the placement of attacker-controlled PHP files in a web-accessible directory, executed as the www-data user.

Nagios Host esensors_websensor_configwizard_func Command Injection Remote Code Execution Vulnerability

Nagios Host esensors_websensor_configwizard_func Command Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Nagios Host. Authentication is required to exploit this vulnerability. The specific flaw exists within the esensors_websensor_configwizard_func method. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-28249.

Nagios Host zabbixagent_configwizard_func Command Injection Remote Code Execution Vulnerability

Nagios Host zabbixagent_configwizard_func Command Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Nagios Host. Authentication is required to exploit this vulnerability. The specific flaw exists within the zabbixagent_configwizard_func method. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-28250.

Nagios Host monitoringwizard Command Injection Remote Code Execution Vulnerability

Nagios Host monitoringwizard Command Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Nagios Host. Authentication is required to exploit this vulnerability. The specific flaw exists within the monitoringwizard module. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-28245.

Nagios XI Network Monitor Graph Explorer Component < 1.3 Authenticated Command Injection

Nagios XI Network Monitor prior to Graph Explorer component version 1.3 contains a command injection vulnerability in `visApi.php`. An authenticated user can inject system commands via unsanitized parameters such as `host`, resulting in remote code execution.

Nagios XI Privilege Escalation via Writable PHP Include Executed with Sudo

Nagios XI versions prior to 2026R1.1 are vulnerable to local privilege escalation due to an unsafe interaction between sudo permissions and application file permissions. A user‑accessible maintenance script may be executed as root via sudo and includes an application file that is writable by a lower‑privileged user. A local attacker with access to the application account can modify this file to introduce malicious code, which is then executed with elevated privileges when the script is run. Successful exploitation results in arbitrary code execution as the root user.

Nagios XI < 2026R1 Configuration Wizard Authenticated Command Injection

Nagios XI < 2026R1 is vulnerable to an authenticated command injection vulnerability within the MongoDB Database, MySQL Query, MySQL Server, Postgres Server, and Postgres Query wizards. It is possible to inject shell characters into arguments provided to the service and execute arbitrary system commands on the underlying host as the `nagios` user.

In NagiosXI 2026R1.0.1 build 1762361101, Dashboard parameters lack proper filtering, allowing any authenticated user to exploit a SQL Injection vulnerability.

NagiosXI 2026R1.0.1 build 1762361101 is vulnerable to Directory Traversal in /admin/coreconfigsnapshots.php.

Nagios XI < 2011R1.9 XSS via xiwindow Variables Affecting Permalinks

Nagios XI versions prior to 2011R1.9 are vulnerable to cross-site scripting (XSS) via the handling of xiwindow variables used to build permalinks in the web interface. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.