CVE-2026-48553

Description

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.

References

• https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog
• https://www.nagios.com/security-disclosures/nagios-core/
• https://www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection