CVE-2026-48553
Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.7
Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
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.
- Record
CVE-2026-48553- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
EUVDEUVD-2026-57345
7.7
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.
- Record
EUVD-2026-57345- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r6wg-9vj9-rm67
7.7
Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to authenticated remote...
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.
- Record
GHSA-r6wg-9vj9-rm67- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
NVD
7.7
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.
- Record
CVE-2026-48553- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-78
- Updated
- 2026-11-02
OSV
7.7
Nagios Core / XI Authenticated RCE via Custom-Variable Macro Injection
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.
- Record
CVE-2026-48553- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-78
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-48553
7.7
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.
- Record
DEBIAN-CVE-2026-48553- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-48553
7.7
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.
- Record
UBUNTU-CVE-2026-48553- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nagios4Debian:12 |
before 4.4.6-4+deb12u2, plus listed versions 4.4.6-44.4.6-4+deb12u1 |
4.4.6-4+deb12u2 |
nagios4Debian:13 |
before 4.4.6-4.1+deb13u2, plus listed versions 4.4.6-4.14.4.6-4.1+deb13u1 |
4.4.6-4.1+deb13u2 |
nagios4Debian:14 |
before 4.5.14+ds-1, plus listed versions 4.4.6-4.14.5.12+ds-1 |
4.5.14+ds-1 |
nagios4Ubuntu:20.04:LTS |
All versions, plus listed versions 4.3.4-34.3.4-3ubuntu0.1 |
None known |
nagios4Ubuntu:22.04:LTS |
All versions, plus listed versions 4.4.6-44.4.6-4ubuntu0.22.04.1 |
None known |
nagios4Ubuntu:24.04:LTS |
All versions, plus listed versions 4.4.6-44.4.6-4ubuntu0.24.04.1 |
None known |
nagios4Ubuntu:26.10 |
All versions, plus listed versions 4.4.6-4.1ubuntu2 |
None known |
nagios4Ubuntu:26.04:LTS |
All versions, plus listed versions 4.4.6-4.1ubuntu14.4.6-4.1ubuntu2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-48553 is a high vulnerability (CVSS 7.7) in Nagios Enterprises Xi, published August 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.97%, the 61st percentile. Fixed in nagios4 4.4.6-4+deb12u2.
References
nagios.com/security-disclosures/nagios-core
github.com/NagiosEnterprises/nagioscore/blob/master/Changelog
vulncheck.com/advisories/nagios-core-xi-authenticated-rce-via-custom-variable-macro-injection
nvd.nist.gov/vuln/detail/CVE-2026-48553
github.com/advisories/GHSA-r6wg-9vj9-rm67
github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48553.json
security-tracker.debian.org/tracker/CVE-2026-48553
ubuntu.com/security/CVE-2026-48553
cve.org/CVERecord?id=CVE-2026-48553