Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-78.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Nagios Enterprises, LLC. | Nagios Core | before 4.5.13 | 4.5.13 | Patch available | CNA |
| Nagios Enterprises, LLC. | Nagios XI | before 2026R1.5 | 2026R1.5 | Patch available | CNA |
- Nagios Core VendorNagios Enterprises, LLC. Affected before 4.5.13 Fixed in 4.5.13 Patch available CNA
- Nagios XI VendorNagios Enterprises, LLC. Affected before 2026R1.5 Fixed in 2026R1.5 Patch available CNA
Remediation
- Fix · CNA Nagios Core (Nagios Enterprises, LLC.) Fixed in 4.5.13
- Fix · CNA Nagios XI (Nagios Enterprises, LLC.) Fixed in 2026R1.5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-48553
- 2026-10-03 Alias added: GHSA-r6wg-9vj9-rm67
References
Patch 1
Other 1
More Nagios Enterprises, LLC. vulnerabilities
- TI-2012-05452 Nagios XI Network Monitor Graph Explorer Component < 1.3 Authenticated Command Injection CVSS 4.0HIGH 8.6
- TI-2026-84257 OS command injection in Nagios XI via MIB upload CVSS 4.0HIGH 8.6
- TI-2026-35913 Nagios Core / XI Authenticated RCE via Unfiltered NOTIFICATION-Family Macro Substitution CVSS 4.0HIGH 7.7
- TI-2026-35908 Nagios Core / XI CSRF via cmd.cgi Double-Submit Cookie CVSS 4.0MEDIUM 6.9
- TI-2026-35907 Nagios Core CSRF via cmd.cgi CVSS 4.0MEDIUM 6.9
- TI-2026-35910 Nagios Core / XI CSRF Protection Bypass via Double-Submit Cookie CVSS 4.0MEDIUM 6.1
Sources
- CVE-2026-48553 · CVE Program
- CVE-2026-48553 · NVD
- FIRST EPSS
- GHSA-r6wg-9vj9-rm67 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences