Nagios Core <4.5.13 & XI <2026R1.5: Auth RCE via NRDP macro injection
CVE-2026-48553 Published on August 12, 2026
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.
Vulnerability Analysis
CVE-2026-48553 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Shell injection Vulnerability?
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
CVE-2026-48553 has been classified to as a Shell injection vulnerability or weakness.
Products Associated with CVE-2026-48553
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Affected Versions
Nagios Enterprises, LLC. Nagios Core:- Before 4.5.13 is affected.
- Before 2026R1.5 is affected.