{"id":"CVE-2026-48553","aliases":["DEBIAN-CVE-2026-48553","EUVD-2026-57345","GHSA-r6wg-9vj9-rm67","UBUNTU-CVE-2026-48553"],"status":"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.","severity":{"version":"4.0","score":7.7,"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00966,"percentile":0.62197,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-78"],"published":"2026-08-12T16:46:35Z","modified":"2026-10-28T02:31:10Z","fixes":[{"ecosystem":"Debian:12","package":"nagios4","fixed_in":["4.4.6-4+deb12u2"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"nagios4","fixed_in":["4.4.6-4.1+deb13u2"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"nagios4","fixed_in":["4.5.14+ds-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.6-4+deb12u2"}]}],"versions":["4.4.6-4","4.4.6-4+deb12u1"]},{"source":"osv","ecosystem":"Debian:13","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.6-4.1+deb13u2"}]}],"versions":["4.4.6-4.1","4.4.6-4.1+deb13u1"]},{"source":"osv","ecosystem":"Debian:14","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.14+ds-1"}]}],"versions":["4.4.6-4.1","4.5.12+ds-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.4-3","4.3.4-3ubuntu0.1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4","4.4.6-4ubuntu0.22.04.1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4","4.4.6-4ubuntu0.24.04.1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4.1ubuntu2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"nagios4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.4.6-4.1ubuntu1","4.4.6-4.1ubuntu2"]}],"products":[{"vendor":"nagios enterprises","product":"nagios xi"},{"vendor":"nagios enterprises, llc.","product":"nagios core"},{"vendor":"nagios enterprises, llc.","product":"nagios xi"},{"vendor":"open source","product":"nagios core"}],"references":[{"url":"https://www.nagios.com/security-disclosures/nagios-core/","tags":["vendor-advisory","patch","fix","report"]},{"url":"https://github.com/NagiosEnterprises/nagioscore/blob/master/Changelog","tags":["release-notes","advisory","report"]},{"url":"https://www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48553","tags":["advisory"]},{"url":"https://www.nagios.com/security-disclosures/nagios-core"},{"url":"https://github.com/advisories/GHSA-r6wg-9vj9-rm67"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48553.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-48553","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-48553","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-48553","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-48553","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.","status":"published","published":"2026-08-12T16:46:35.837Z","modified":"2026-08-14T16:50:00.508Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-78"],"updated_at":"2026-11-02T13:50:49.872037Z"}],"euvd":[{"id":"EUVD-2026-57345","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.","status":"published","published":"2026-08-12T16:46:35Z","modified":"2026-08-14T16:50:00Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high"}],"updated_at":"2026-11-02T18:01:54.570698Z"}],"ghsa":[{"id":"GHSA-r6wg-9vj9-rm67","title":"Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to authenticated remote...","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.","status":"published","published":"2026-08-12T18:31:20Z","modified":"2026-08-12T18:31:28Z","cvss":[{"version":"4.0","score":7.7,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-78"],"updated_at":"2026-11-02T15:10:23.360888Z"}],"nvd":[{"id":"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.","status":"published","published":"2026-08-12T17:17:27.697Z","modified":"2026-09-08T20:28:37.587Z","cvss":[{"version":"4.0","score":7.7,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-78"],"updated_at":"2026-11-02T14:12:37.217486Z"}],"osv":[{"id":"CVE-2026-48553","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.","status":"published","published":"2026-08-12T16:46:35.837Z","modified":"2026-10-28T02:31:10.850185187Z","cvss":[{"version":"4.0","score":7.7,"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","level":"high"}],"cwes":["CWE-78"],"updated_at":"2026-11-02T15:45:06.701612Z"},{"id":"DEBIAN-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.","status":"published","published":"2026-08-12T17:17:27.697Z","modified":"2026-10-14T06:00:20.233540626Z","cvss":[{"version":"4.0","score":7.7,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"UBUNTU-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.","status":"published","published":"2026-08-12T17:17:00Z","modified":"2026-10-17T13:00:22.72180795Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"},{"version":"4.0","score":7.7,"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","level":"high"}],"updated_at":"2026-11-02T16:56:33.391918Z"}]}}