# CVE-2026-48553: nagios4: Nagios Core before 4.5.13 and Nagios XI before 2026R1.5 are vulnerable to authenticated remote code execution via cus...

CVE-2026-48553 is fixed in nagios4 on 1 platform, first by DEBIAN-CVE-2026-48553, released August 12, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-48553
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0097
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 12, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | nagios4 Debian 12.15 (bookworm) | 4.4.6-4+deb12u2 | [DEBIAN-CVE-2026-48553](https://patchblox.com/security/data/fix/linux/debian-cve-2026-48553.md) | Aug 12, 2026 |
| Linux | nagios4 Debian 13.5 (trixie) | 4.4.6-4.1+deb13u2 | [DEBIAN-CVE-2026-48553](https://patchblox.com/security/data/fix/linux/debian-cve-2026-48553.md) | Aug 12, 2026 |
| Linux | nagios4 Debian 14 | 4.5.14+ds-1 | [DEBIAN-CVE-2026-48553](https://patchblox.com/security/data/fix/linux/debian-cve-2026-48553.md) | Aug 12, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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