Nagios XI Local Privilege Escalation Vulnerability Allowing Arbitrary Code Execution as Root

A local privilege escalation vulnerability has been identified in Nagios XI versions prior to 2026R1.1. This issue arises from an unsafe interaction between sudo permissions and application file permissions, allowing a local attacker with access to the application account to execute a user-accessible maintenance script as root via sudo. The script includes an application file that can be modified by a lower-privileged user. By introducing malicious code into this file, the attacker can achieve arbitrary code execution with elevated privileges when the script is executed.

Impact

Exploitation of this vulnerability allows for arbitrary code execution as the root user.

Remediation

Users are advised to update Nagios XI to version 2026R1.1 or later.