cnspec
Open source, cloud-native security and policy project
cnspec assesses your entire infrastructure's security and compliance. It finds vulnerabilities and misconfigurations across public and private cloud environments, Kubernetes clusters, containers, container registries, servers, endpoints, SaaS products, infrastructure as code, APIs, and more.
A powerful policy as code engine, cnspec is built upon Mondoo's security data fabric. It comes configured with default security policies that run right out of the box. It's both fast and simple to use!
Quick start
bash -c "$(curl -sSL https://install.mondoo.com/sh)"
cnspec scan local
Installation
Install cnspec with our installation script:
Linux and macOS
bash -c "$(curl -sSL https://install.mondoo.com/sh)"
Windows
Set-ExecutionPolicy Unrestricted -Scope Process -Force;
[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072;
iex ((New-Object System.Net.WebClient).DownloadString('https://install.mondoo.com/ps1'));
Install-Mondoo;
If you prefer manual installation, you can find the cnspec packages in our releases.
Run a scan with policies
Use the cnspec scan subcommand to check local and remote targets for misconfigurations and vulnerabilities.
Local scan
This command evaluates the security of your local machine:
cnspec scan local
Remote scan targets
You can also specify remote targets to scan. For example:
# to scan a docker image:
cnspec scan docker image ubuntu:22.04
# scan public ECR registry
aws ecr-public get-login-password --region us-east-1 | docker login --username AWS --password-stdin public.ecr.aws/r6z5b8t4
cnspec scan docker image public.ecr.aws/r6z5b8t4
# to scan an AWS account using the local AWS CLI config
cnspec scan aws
# scan an EC2 instance with EC2 Instance Connect
cnspec scan aws ec2 instance-connect root@i-1234567890abcdef0
# to scan a Kubernetes cluster via your local kubectl config or a local manifest file
cnspec scan k8s
cnspec scan k8s manifest.yaml
# to scan a GitHub repository
export GITHUB_TOKEN=<personal_access_token>
cnspec scan github repo <org/repo>
:books: To learn more, read the cnspec docs.
Policies
cnspec policies are built on the concept of policy as code. cnspec comes with default security policies configured for all supported targets. The default policies are available in the content directory of this repository.
Vulnerability scan
cnspec scans for vulnerabilities in a wide range of platforms. Vulnerability scanning is not restricted to container images; it works for build and runtime as well.
NOTE: Vulnerability scanning requires the client to be logged into Mondoo Platform.
Examples
# scan container image
cnspec vuln docker debian:12
# scan aws instance via EC2 instance connect
cnspec vuln aws ec2 instance-connect root@i-1234567890abcdef0
# scan instance via SSH
cnspec vuln ssh user@host
# scan windows via SSH or Winrm
cnspec vuln ssh user@host --ask-pass
cnspec vuln winrm user@host --ask-pass
# scan VMware vSphere ESXi hosts
cnspec vuln vsphere user@host --ask-pass
# scan Linux, Windows
cnspec vuln local
| Platform | Versions |
|---|
| Alpine | 3.10 - 3.24 |
| AlmaLinux | 8, 9, 10 |
| Amazon Linux | 1, 2, 2023 |
| Arch Linux | Rolling |
| CentOS | 6, 7, 8, Stream |
| Debian | 8, 9, 10, 11, 12, 13 |
| Fedora | 30 - 44 |
| openSUSE | Leap 15, Leap 16 |
| Oracle Linux | 6, 7, 8, 9, 10 |
| Photon Linux | 2, 3, 4, 5 |
| Red Hat Enterprise Linux | 6, 7, 8, 9, 10 |
| Rocky Linux | 8, 9, 10 |
| SUSE Linux Enterprise | 12, 15, 16 |
| Ubuntu | 18.04, 20.04, 22.04, 24.04, 26.04 |
| VMware vSphere ESXi | 6, 7, 8, 9 |
| Windows | 10, 11, 2016, 2019, 2022, 2025 |
cnspec interactive shell
cnspec also provides an interactive shell to explore assertions. It helps you understand the assertions that security policies use, as well as write your own policies. It's also a great way to interact with both local and remote targets on the fly.
Local system shell
cnspec shell local
The shell provides a help command for information on the resources that power cnspec. Running help without any arguments lists all of the available resources and their fields. You can also run help <resource> to get more detail on a specific resource. For example:
cnspec> help ports
ports: TCP/IP ports on the system
list []port: List of all TCP/IP ports
listening []port: All listening ports
The shell uses auto-complete, which makes it easy to explore.
Once inside the shell, you can enter MQL assertions like this:
> ports.listening.none( port == 23 )
To clear the terminal, type clear.
To exit, either hit CTRL + D or type exit.
Prioritize risks that matter with Mondoo Platform
The Mondoo unified security platform finds and prioritizes vulnerabilities and misconfigurations that pose the highest risk to your business. Mondoo's security data fabric analyzes the threat and exposure of every finding within the unique context of your infrastructure. Instead of a flood of irrelevant security alerts, Mondoo shows you how you can make an immediate and significant impact on your security posture.
To get started, contact us.
To learn about Mondoo Platform, read the Mondoo Platform docs or visit mondoo.com.
Register cnspec with Mondoo Platform
To use cnspec with Mondoo Platform, generate a token in the Mondoo App, then run:
cnspec login --token TOKEN
Once authenticated, you can scan any target:
cnspec scan <target>
cnspec returns the results from the scan to STDOUT and to Mondoo Platform.
With an account on Mondoo Platform, you can upload policies:
cnspec bundle upload mypolicy.mql.yaml
Custom policies
A cnspec policy is simply a YAML file that lets you express any security rule or best practice for your fleet.
A few examples can be found in the examples folder in this repo. You can run any of these policies:
cnspec scan local -f examples/example.mql.yaml
If you're interested in writing your own policies or contributing policies back to the cnspec community, read Mondoo's Policy Authoring Guide.
Supported targets
| Target | Provider | Example |
|---|
| Active Directory domains | activedirectory | cnspec scan activedirectory --dc DC_HOSTNAME --user USER --password PASSWORD |
| Alibaba Cloud accounts | alicloud | cnspec scan alicloud --access-key-id KEY_ID --access-key-secret KEY_SECRET |
| Ansible playbooks | ansible | cnspec shell ansible YOUR_PLAYBOOK.yml |
| Apache Cassandra clusters | cassandra | cnspec scan cassandra HOST --user USER --ask-pass |
| Arista network devices | arista | cnspec scan arista DEVICE_PUBLIC_IP --ask-pass |
| Atlassian organizations | atlassian admin | cnspec shell atlassian admin --admin-token YOUR_TOKEN |
| Auth0 tenants | auth0 | cnspec scan auth0 --domain TENANT_DOMAIN --client-id CLIENT_ID --client-secret CLIENT_SECRET |
| AWS accounts | aws | cnspec scan aws |
| AWS CloudFormation templates | cloudformation | cnspec scan cloudformation cloudformation_file.json |
| AWS EC2 EBS snapshot | aws ec2 ebs snapshot | cnspec scan aws ec2 ebs snapshot SNAPSHOTID |
| AWS EC2 EBS volume | aws ec2 ebs volume | cnspec scan aws ec2 ebs volume VOLUMEID |
| AWS EC2 Instance Connect | aws ec2 instance-connect | cnspec scan aws ec2 instance-connect ec2-user@INSTANCEID |
| AWS EC2 instances | ssh | cnspec scan ssh user@host |
| Bicep files and ARM templates | bicep | cnspec scan bicep BICEP_FILE_OR_PATH |
| Bitwarden organizations | bitwarden | cnspec scan bitwarden --client-id organization.UUID --client-secret CLIENT_SECRET |
Agent skills
cnspec includes agent skills that give coding agents MQL expertise and policy navigation capabilities. Skills work across Claude Code, Cursor, Gemini CLI, and Codex.
| Skill | Description |
|---|
| mql | MQL query development with syntax guidance, platform-specific patterns, and schema discovery |
| policy-graph | Navigate policy bundles using graph commands — search, trace compliance mappings, explore structure |
See skills/README.md for installation instructions and details.
What's next?
There are so many things cnspec can do, from testing your entire fleet for vulnerabilities to gathering information and creating reports for auditors. With its custom policies, cnspec can scan any component you care about!
Explore our:
Join the community!
Our goal is to secure all layers of your infrastructure. If you need support or want to get involved with the development of cnspec, join our community today and let's grow it together!
Development
See AGENTS.md for information on building, testing, and contributing to cnspec.
Legal
- Copyright: 2018-2026, Mondoo, Inc.
- License: BUSL 1.1
- Authors: Christoph Hartmann, Dominik Richter
