CVE-2026-48553 json
Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
published 2026-08-12 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-57345
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 61%
- public exploits
- 0
- none known
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.
Patch / fix
- Nagios Enterprises, LLC. Nagios Core 4.5.13
- Nagios Enterprises, LLC. Nagios XI 2026R1.5
- nagios4 Debian 12 4.4.6-4+deb12u2
- nagios4 Debian 13 4.4.6-4.1+deb13u2
- nagios4 Debian 14 4.5.14+ds-1
debian advisories DEBIAN-CVE-2026-48553
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 mo ago
Exploit prediction
0.97% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.7 | 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 |
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 7.7 | 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 |
Affected products
- Nagios Enterprises, LLC. Nagios Core
- Nagios Enterprises, LLC. Nagios XI
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
-
nagios.com
/security-disclosures/nagios-core/
vendor-advisory, patch
-
github.com
/NagiosEnterprises/nagioscore/blob/master/Changelog
release-notes
-
vulncheck.com
/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection
third-party-advisory
Sources
- CVE List CVE-2026-48553
- NVD CVE-2026-48553
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