RCE in Nagios Enterprises, Llc. Core
CVE-2026-48553
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.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.010 (60.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.010 · change: +0.004
Affected products
- Nagios Enterprises, Llc. Core — versions 0
- Nagios Enterprises, Llc. Xi — versions 0
Weakness classification (CWE)
References
- github.com/NagiosEnterprises/nagioscore/blob/master/Changelog (release-notes)
- www.nagios.com/security-disclosures/nagios-core/ (vendor-advisory, patch)
- www.vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variab… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-48553?
- CVE-2026-48553 is a high-severity vulnerability in Nagios Enterprises, Llc. Core, classified under OS Command Injection. CVSS score: 7.5/10. Published 2026-08-12.
- How severe is CVE-2026-48553?
- High severity. CVSS v3 base score is 7.5 out of 10.