CVE-2026-48553

Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection

Published Aug 12, 2026 CVSS 4.0 · 7.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4832-1 nagios4 security update
Debian DSA Debian DSA DSA-6556-1 nagios4 security update
History
Type Values Removed Values Added
CPEs cpe:2.3:a:nagios:nagios_core:*:*:*:*:*:*:*:*
cpe:2.3:a:nagios:nagios_xi:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Nagios
Nagios nagios Core
Nagios nagios Xi
Vendors & Products Nagios
Nagios nagios Core
Nagios nagios Xi
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 14, 2026, 4:50 PM
Reserved
May 21, 2026, 6:34 PM
Status
Awaiting Analysis
Published
Aug 12, 2026, 5:17 PM
Modified
Sep 8, 2026, 8:28 PM