Nagios Enterprises Nagios Core/Nagios XI up to 4.5.12/2026R1.4 Nagios Remote Data Processor os command injection

Summaryinfo

A vulnerability marked as very critical has been reported in Nagios Enterprises Nagios Core and Nagios XI up to 4.5.12/2026R1.4. Affected is an unknown function of the component Nagios Remote Data Processor. This manipulation causes os command injection. This vulnerability appears as CVE-2026-48553. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Nagios Enterprises Nagios Core and Nagios XI up to 4.5.12/2026R1.4. It has been declared as very critical. Affected by this vulnerability is an unknown code of the component Nagios Remote Data Processor. The manipulation with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at nagios.com. This vulnerability is known as CVE-2026-48553 since 05/21/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/12/2026). MITRE ATT&CK project uses the attack technique T1202 for this issue.

Upgrading to version 4.5.13 or 2026R1.5 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Log Management Software

Vendor

• Nagios Enterprises

Name

• Nagios Core
• Nagios XI

Version

• 4.5.0
• 4.5.1
• 4.5.2
• 4.5.3
• 4.5.4
• 4.5.5
• 4.5.6
• 4.5.7
• 4.5.8
• 4.5.9
• 4.5.10
• 4.5.11
• 4.5.12
• 2026R1.0
• 2026R1.1
• 2026R1.2
• 2026R1.3
• 2026R1.4

License

• open-source

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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