{"id":"CVE-2026-48553","state":"PUBLISHED","title":"Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection","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.","publishedAt":"2026-08-12T16:46:35.837Z","updatedAt":"2026-08-14T16:50:00.508Z","severity":{"score":7.7,"label":"High","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["Nagios Enterprises, LLC. Nagios Core","Nagios Enterprises, LLC. Nagios XI"],"affected":[{"vendor":"Nagios Enterprises, LLC.","product":"Nagios Core","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"4.5.13","versionType":"semver"}]},{"vendor":"Nagios Enterprises, LLC.","product":"Nagios XI","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2026R1.5","versionType":"custom"}]}],"references":["https://www.nagios.com/security-disclosures/nagios-core/","https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog","https://www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection"],"weaknesses":["CWE-78"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48553.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48553","state":"PUBLISHED","datePublished":"2026-08-12T16:46:35.837Z","dateUpdated":"2026-08-14T16:50:00.508Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-05-21T18:34:46.418Z"},"containers":{"cna":{"title":"Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Nagios Enterprises, LLC.","product":"Nagios Core","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"4.5.13","versionType":"semver"}]},{"vendor":"Nagios Enterprises, LLC.","product":"Nagios XI","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2026R1.5","versionType":"custom"}]}],"references":[{"url":"https://www.nagios.com/security-disclosures/nagios-core/","name":"Security Disclosures","tags":["vendor-advisory","patch"]},{"url":"https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog","name":"Changelog","tags":["release-notes"]},{"url":"https://www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.7,"vectorString":"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"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","version":"3.1","baseSeverity":"HIGH","baseScore":7.5,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-78","lang":"en","description":"Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-14T16:50:00.508Z"},"datePublic":"2026-08-05T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:nagios:nagios_core:*:*:*:*:*:*:*:*","versionEndExcluding":"4.5.13"},{"vulnerable":true,"criteria":"cpe:2.3:a:nagios:nagios_xi:*:*:*:*:*:*:*:*","versionEndExcluding":"2026r1.5"}]}]}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"vulncheck"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-12T17:55:13.472460Z","id":"CVE-2026-48553","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-12T19:19:20.109Z"}}]}}}