Catalog / Observability & monitoring

Nagios

Host and service monitoring with plugins and notifications

CIS Level 1 hardened Ubuntu 24.04 LTS image by Lynxroute · unique credentials at first boot · CVE-scanned · SBOM and CIS report inside

AWS Marketplace4.5.14↗ Azure Marketplace4.5.14↗
Availability and pricing
CloudVersionSoftware priceLast build
AWS Marketplace
EC2 AMI · all commercial regions
4.5.14$0.05/hr
Recommended instance: t3.medium · 5-day free trial
2026-10-23Listing ↗
Azure Marketplace
VM image · plan payg-gen2 · Gen2
4.5.14$0.028/vCPU/hr
Recommended VM: Standard_D2s_v3
2026-10-24Listing ↗

Software price only; cloud infrastructure is billed separately by the provider. Prices in USD.

Image facts
Base OSUbuntu 24.04 LTS
HardeningCIS Level 1, Ubuntu 24.04 LTS (tailored)
LicenseGPL-2.0
UpstreamNagios Core Development Team
Machine-readableproduct.json · catalog.json
What is Nagios

Nagios Core is one of the longest-established open source monitoring servers for hosts, services and network devices. It is a set of compiled C daemons with an Apache CGI and PHP web interface, and it deliberately keeps no SQL database: current state, retention and the event log live in flat files, which is what makes it light enough to watch hundreds of hosts from a small instance. Monitoring is done by check plugins, small executables that return a status and a line of output, so anything you can write a script for can be monitored. This image ships Nagios Core 4.5.14 with Nagios Plugins 2.5, covering ping, disk, load, users, processes, SSH, HTTP, SMTP, SNMP, DNS, NTP and many more. Scheduling, state flapping detection, dependencies, escalations, notification commands and an external command pipe are all part of the core. GPL-2.0 license, no vendor lock-in.

What the Lynxroute image adds

Security hardening:

  • Web password generated at first boot, unique per instance, stored only as a bcrypt hash - the image itself ships a locked account with no usable credential
  • Web interface served by Apache bound to 127.0.0.1 only, with nginx terminating TLS on 443 in front of it
  • Self-signed certificate out of the box and Certbot pre-installed, so a CA-signed certificate is one command away
  • Vendor update checks disabled - the instance does not report its version to any third party
  • The monitoring daemon runs unprivileged with a restricted umask, and the compiler toolchain is removed from the shipped image
  • UFW firewall pre-configured - SSH 22 and HTTPS 443; port 80 only redirects to HTTPS and carries the certificate-issuance challenge
  • fail2ban, AppArmor
  • CVE scan - every image is scanned for vulnerabilities before release

OS hardening (CIS Level 1):

  • CIS Ubuntu 24.04 LTS Level 1 benchmark applied via ansible-lockdown
  • auditd, SSH hardening, Kernel hardening, IMDSv2 enforced

Compliance artifacts:

  • SBOM - CycloneDX 1.6 at /etc/lynxroute/sbom.json
  • CIS Conformance Report at /etc/lynxroute/cis-report.html
  • CIS Tailored Profile at /usr/share/doc/lynxroute/CIS_TAILORED_PROFILE.md
Deploy

Launch in one command

Credentials are generated at first boot and written to /root/nagios-credentials.txt.

# subscribe once on the AWS Marketplace listing, then:
aws ec2 run-instances \
  --image-id resolve:ssm:/aws/service/marketplace/prod-jm7yiikvcovbu/latest \
  --instance-type t3.medium --key-name my-key --security-group-ids sg-xxxxxxxx
# accept the plan terms once, then:
az vm image terms accept --publisher lynxroute --offer nagios --plan payg-gen2
az vm create -g my-rg -n nagios --size Standard_D2s_v3 \
  --image lynxroute:nagios:payg-gen2:latest --admin-username azureuser --generate-ssh-keys
Release notes

Latest release

The most recent release with notes; the full release history is in product.json.

Nagios Core 4.5.14 r2

AWS · 2026-10-23Azure · 2026-10-24
  • Security: fixes PHP2Shell (CVE-2026-109618, CVE-2026-109619), an unauthenticated remote code execution flaw in PHP, by shipping Ubuntu php8.3 8.3.6-0ubuntu0.24.04.13 (USN-8948-1). Every earlier image of this product carries the vulnerable PHP; replace running instances or run: sudo apt-get update && sudo apt-get install --only-upgrade "php8.3*"
  • The application version is unchanged (Nagios Core 4.5.14); this is a security rebuild
  • The Nagios web interface runs its PHP pages through Apache mod_php, which this rebuild patches
  • Rebuilt on the latest CIS Level 1 hardened Ubuntu 24.04 LTS base, picking up every operating-system security update published since the previous build