{"id":"CVE-2026-48553","summary":"Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection","details":"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.","modified":"2026-09-10T03:30:20.196004292Z","published":"2026-08-12T16:46:35.837Z","database_specific":{"unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"fixed":"2026R1.5"}]}],"cna_assigner":"VulnCheck","cwe_ids":["CWE-78"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48553.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48553.json"},{"type":"ADVISORY","url":"https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48553"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection"},{"type":"FIX","url":"https://www.nagios.com/security-disclosures/nagios-core/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nagiosenterprises/nagioscore","events":[{"introduced":"0"},{"fixed":"367ec800bfbecf1ca1e857fe73bdb5fba5cc9003"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"0"},{"fixed":"4.5.13"}]}}],"versions":["nagios-4.5.12","nagios-4.5.11","nagios-4.5.10","nagios-4.5.9","nagios-4.5.8","nagios-4.5.7","nagios-4.5.6","nagios-4.5.5","nagios-4.5.4","nagios-4.5.3","nagios-4.5.2","nagios-4.5.1","nagios-4.5.0","nagios-4.4.14","nagios-4.4.13","nagios-4.4.12","nagios-4.4.11","nagios-4.4.10","nagios-4.4.9","nagios-4.4.8","nagios-4.4.7","nagios-4.4.6","nagios-4.4.5","nagios-4.4.4","nagios-4.4.3","nagios-4.4.3rc1","nagios-4.4.1","nagios-4.4.0","nagios-4.3.4","nagios-4.3.3","nagios-4.3.2","nagios-4.3.1","release-4.3.0","nagios-4.3.0","release-4.2.4","nagios-4.2.2","4.2.1","nagios-4.1.1","nagios-4.1.0","nagios-4.1.0rc2","nagios-4.0.6","nagios-4.0.5","nagios-4.0.4","nagios-4.0.0","nagios-4.0.0-beta4","nagios-4.0.0-beta3","nagios-4.0.0-beta2","nagios-4.0.0-beta1","nagios-3.4.1","nagios-3.4.0","nagios-3.3.1","nagios-3.2.3","nagios-3.2.2","nagios-3.2.1","nagios-3.2.0","nagios-3.1.2","nagios-3.1.1","nagios-3.1.0","nagios-3.0.6","nagios-3.0.5","nagios-3.0.4","nagios-3.0.3","nagios-3.0.2","nagios-3.0.1","nagios-3.0","nagios-3.0rc3","nagios-3.0rc2","nagios-3.0rc1","nagios-3.0b7","nagios-3.0b6","nagios-3.0b5","nagios-3.0b4","nagios-3.0b3","nagios-3.0b2","nagios-3.0b1","nagios-3.0a5","nagios-3.0a4","nagios-3.0a3","nagios-3.0a2","nagios-3.0a1","nagios-2.0","nagios-2.0rc1","nagios-2.0b6","nagios-2.0.b5","nagios-2.0b4","nagios-2.0b3","nagios-2.0b2","nagios-2.0b1","nagios-1.0b6","nagios-1.0b5","nagios-1.0b4","nagios-1.0b3","nagios-1.0b2","nagios-1.0b1","nagios-1.0a7","nagios-1.0a6"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48553.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}