What is the best open-source AWS security scanner in 2026?

It depends on your use case. Prowler is the most comprehensive with 572 AWS checks across 83 services (plus 13 other cloud providers for ~1,242 total checks) and 41 compliance frameworks - best for enterprise compliance audits and multi-cloud coverage. cloud-audit is best for quick one-off AWS audits and CI/CD gating, with 94 checks that each include copy-paste remediation (AWS CLI + Terraform), plus CLI-native attack chain detection that correlates findings into exploitable attack paths. ScoutSuite has not been updated since May 2024.

Is ScoutSuite still maintained?

No. ScoutSuite's last release was v5.14.0 in May 2024. There are 239 open issues and 49 open pull requests with no maintainer response. It still works for basic scans, but it is falling behind on newer AWS services and API changes. Consider Prowler or cloud-audit as alternatives.

How do I compare AWS security scan results over time?

cloud-audit has a built-in diff CLI command that compares two scan JSON files and shows new, fixed, and unchanged findings with CI-friendly exit codes. Prowler offers scan comparison through their paid SaaS platform and self-hosted Prowler App, but the open-source CLI does not have a standalone diff command. ScoutSuite has no drift tracking.

Can I run AWS security scanners in CI/CD pipelines?

Yes. Both Prowler and cloud-audit support CI/CD integration. cloud-audit outputs SARIF for GitHub Code Scanning, markdown for PR comments, and uses exit codes (0 = clean, 1 = findings) for pipeline gating. Prowler supports CSV, JSON-OCSF, JSON-ASFF, and HTML output formats. Both run in GitHub Actions, GitLab CI, and other CI systems.

Can an open-source tool detect attack chains like Wiz or Orca?

Yes, two open-source tools offer this. The Prowler App (open-source, self-hostable, with an optional hosted Cloud tier) provides graph-based attack path analysis using Neo4j and Cartography with graph queries across the full resource inventory - the most comprehensive open-source approach. cloud-audit (v1.0+) takes a lighter approach with 31 attack chain rules built into the free CLI - for example, a public security group + IMDSv1 + admin IAM role = full account takeover path. Each chain includes an estimated breach cost range in USD based on IBM Cost of a Data Breach data. The tradeoff: Prowler App's graph analysis is more powerful but requires platform infrastructure; cloud-audit runs with pip install and zero setup.

Is Prowler free or paid?

Prowler's open-source CLI is free under Apache 2.0 with all 572 AWS checks and 55 auto-fixers included. The Prowler App is also open-source (Apache 2.0) and can be self-hosted - it adds scan comparison, graph-based attack path analysis (Cartography + Neo4j), and dashboards. An optional hosted Prowler Cloud tier is available for teams that prefer managed hosting. Prowler also has a free MCP Server (open-source, on PyPI) for AI-assisted workflows. cloud-audit is free (MIT license) with all features included in the CLI - attack chains, diff command, breach cost estimation, MCP Server, remediation output, SARIF - there is no paid tier.

Prowler vs ScoutSuite vs cloud-audit: 572 Checks vs 94

Quick answer: Prowler, ScoutSuite, and cloud-audit are the three leading open-source AWS security scanners in 2026. Prowler runs 572 AWS checks across 83 services with 41 compliance frameworks. cloud-audit runs 94 curated checks with CLI + Terraform remediation and 31 attack chain rules. ScoutSuite has not been updated since May 2024. This is a practical comparison based on real scans.

TL;DR: Prowler has the most checks (572 AWS across 83 services), covers 41 compliance frameworks, and offers graph-based attack path analysis through the Prowler App (Cartography + Neo4j) - best for enterprise compliance and large-scale security programs. cloud-audit (94 checks) is fastest for one-off AWS audits and CI/CD gating, with CLI-native attack chains, breach cost estimation, and copy-paste remediation - all free, zero infrastructure. Both offer free MCP Servers for AI integration. ScoutSuite has not been updated since May 2024 and is effectively unmaintained. Disclosure: I am the author of cloud-audit.

AWS security scanners compared (2026): Prowler runs 572 AWS checks across 83 services with 41 compliance frameworks (broadest coverage, Apache 2.0). ScoutSuite has around 200 checks but has not been updated since May 2024. cloud-audit runs 94 curated checks with 31 attack chain rules and CLI-native AWS CLI + Terraform remediation (MIT). All three are free. Each solves different problems at different scales.

AWS Security Scanner Comparison Table

Here’s the practical difference between the three tools as of April 2026:

Feature	Prowler	ScoutSuite	cloud-audit
Checks	572 AWS (~1,242 total across 14 providers)	~200	94
Cloud providers	AWS, Azure, GCP, K8s, M365, GitHub, OCI + 7 more	AWS, Azure, GCP, OCI	AWS only
CIS Benchmark mapping	Full (41 frameworks for AWS)	Partial	62 CIS v3.0 controls (55 automated) with per-control remediation
Remediation	Docs links + `--fixer` (55 fixers across 17 AWS services)	None	CLI + Terraform for every finding
Attack path analysis	Prowler App (Neo4j + Cartography, 78 AWS attack path queries)	No	CLI-native (31 rules, zero infra)
Scan diff / drift tracking	Paid platform (Prowler Cloud / self-hosted App)	None	Built-in CLI (`cloud-audit diff`)
Output formats	CSV, JSON-OCSF, JSON-ASFF, HTML	HTML (interactive)	JSON, HTML, Markdown, SARIF
Scan speed (typical account)	10-30 min	5-15 min	Depends on number of components
Cost estimation	No	No	Per-finding and per-chain breach cost ranges (USD)
MCP / AI integration	MCP Server (hub/docs free, app features require API key)	No	MCP Server (full scan, all features free)
Last release	Active (weekly)	May 2024	April 2026 (v1.2.2)
Language	Python	Python	Python
License	Apache 2.0	GPL 2.0	MIT

After reviewing this table, a few things are worth noting:

Prowler is undoubtedly the most comprehensive scanner in this comparison. It covers CIS, PCI-DSS, HIPAA, SOC2, and NIST 800-53 benchmarks in detail. When an auditor shows up for a certification and demands proof of compliance, Prowler is the tool you’re looking for. Its scope surpasses other scanners.

ScoutSuite was a really good tool. Well, it was. Currently, it’s essentially unupdated. The last version (v5.14.0) was released in May 2024. The number of issues on GitHub was growing (239 open issues, 49 open PRs), and there were no answers. And that’s a shame, because the interactive HTML report was a nice feature (if the client wanted to clearly see what was wrong, they could open a single file and get a more or less complete picture). Unfortunately, the lack of updates means that newer AWS services and API changes aren’t included, and therefore, the tool is becoming increasingly outdated.

Cloud-Audit has 94 checks. That’s a fraction of Prowler’s scope, by design. It’s a very young tool, but it does what it was designed for - it deliberately focuses on configuration errors that actually occur and pose a threat during everyday work. Root MFA, public S3, open security groups, unencrypted RDS - the 17 issues I find in almost every AWS account. It doesn’t attempt to cover every compliance framework.

Where it differentiates is how it handles attack paths. Prowler offers attack path analysis through the Prowler App (open-source, self-hostable, with an optional hosted Cloud tier) using Neo4j and Cartography - a powerful graph-based approach with privilege escalation path queries across the full resource inventory. Cloud-audit takes a different approach: 31 attack chain rules that run directly in the CLI with zero additional infrastructure. It also estimates the financial risk of each finding and attack chain in USD, based on IBM Cost of a Data Breach data and published enforcement actions. More on both approaches below.

When to Use Prowler, ScoutSuite, or cloud-audit

Prowler - comprehensive audits and compliance

Use Prowler when:

You need full CIS benchmark coverage with evidence
You are working on SOC2, PCI-DSS, or HIPAA compliance
You are auditing a large organization with complex AWS configurations
You need multi-cloud scanning (AWS + Azure + GCP)
Scan time is irrelevant (10-30 minutes is perfectly sufficient)

Prowler is the industry standard for a reason. The project is well-maintained, has a large community, and covers edge cases that smaller tools simply don’t cover.

The tradeoff is complexity. Prowler offers many configuration options, the results can be overwhelming upon first launch (hundreds of results - here’s how to translate them into an executive report), and scanning takes a long time. For large accounts spanning multiple regions, wait times can exceed 30 minutes.

Prowler’s compliance depth

This deserves its own mention. If you need to generate compliance evidence, Prowler is in a league of its own among open-source tools. Run prowler aws --compliance cis_1.5_aws and you get a structured report mapping every finding to a specific CIS control, with pass/fail status and evidence. For SOC2 or PCI-DSS, the same pattern applies - just swap the compliance flag. That structured mapping is what auditors need, and no other free tool provides it at this depth.

Prowler also has an --fixer flag that can automatically remediate certain findings - 55 auto-fixers covering 17 AWS services (EC2, IAM, S3, CloudTrail, KMS, RDS, GuardDuty, SecurityHub, and more). These fixers work by making direct AWS API calls to change your infrastructure. That covers about 9.6% of Prowler’s 572 AWS checks. The remaining 90% give you documentation links.

ScoutSuite - unmaintained since May 2024

ScoutSuite was a really good tool. It was quick, visual, and you ran it and received a single HTML summary. The interface was also user-friendly, even for non-technical users - it allowed you to browse results by service.

It’s a real shame that the project expired in May 2024. Pull Requests remain untouched, and issues remain unanswered. AWS has since changed significantly, introducing many new services and updating the API. Over time, the tool is becoming increasingly outdated.

As of today, I wouldn’t recommend creating new workflows based on this tool. Are you still using it and it’s working as expected? Okay, fine, but don’t build automation around it.

Cloud-Audit - quick audits and CI/CD

Cloud-Audit is my tool. This tool was created primarily because I needed it. Previously, after every scan, I had to manually perform the same steps, searching for a solution for each finding, writing commands in the CLI, or code in Terraform. As this tool has evolved, these aspects have become automated.

Use Cloud-Audit when:

You want fast scans (speed depends on the number of components in your account)
You need copy-and-paste fixes (AWS CLI + Terraform HCL for each detection)
You integrate with CI/CD and need clear pass/fail exit codes
You want to track differences between scans without setting up additional infrastructure
You want to see how individual findings combine into real attack paths
You want to estimate the financial risk of each finding in dollars
You want AI agents (Claude Code, Cursor) to query your scan results via MCP
You have a small team without a dedicated security team

Don’t use Cloud-Audit when:

You need comprehensive CIS/PCI/HIPAA compliance evidence - use Prowler
You need multi-cloud scanning - use Prowler or Trivy
You need more than 500 checks - use Prowler
You need a mature tool with a large community - use Prowler

Cloud-Audit covers 94 checks. Prowler covers 572 for AWS alone, plus 13 other cloud providers. If you require broad scope or multi-cloud coverage, Prowler is a better choice. Both tools can show you how findings connect into exploitable attack paths - Prowler through the Prowler App with Neo4j graph analysis (open-source self-host or hosted Cloud tier), cloud-audit through its free CLI with 31 built-in rules. The tradeoff: Prowler’s approach is more powerful but requires platform infrastructure; cloud-audit’s runs with pip install and zero setup.

Remediation: CLI and Terraform Fix Commands

And this is really the key reason I started building Cloud-Audit in the first place.

Most scanners do a good job of detecting vulnerabilities. But at the same time, none of them seem to tell you how to fix them. In practice:

Prowler output (simplified):

FAIL - Root account does not have MFA enabled
  Severity: Critical
  Documentation: https://docs.aws.amazon.com/...

You’ll get a link to the documentation. Prowler does have an --fixer flag that can automatically remediate 55 checks across 17 AWS services by making direct AWS API calls. But for the remaining ~90% of checks, you still need to read the documentation, understand the CLI commands, and write Terraform if you’re managing your infrastructure as code. And importantly - Prowler’s fixers mutate your infrastructure directly. There is no Terraform output, no reviewable code. It just changes things.

Cloud-Audit output with -R flag:

CRITICAL  Root account without MFA enabled
Resource:   arn:aws:iam::123456789012:root
Compliance: CIS 1.5
CLI:        aws iam create-virtual-mfa-device --virtual-mfa-device-name root-mfa
Terraform:  resource "aws_iam_virtual_mfa_device" "root" { ... }
Docs:       https://docs.aws.amazon.com/IAM/latest/UserGuide/...

Using the --export-fixes flag gives you a ready-to-run script with CLI commands. You open it, browse, select what you want to fix, and run it.

And to be clear, this isn’t a better or worse approach than Prowler - it’s just different. Prowler goes wide (572 AWS checks) with direct API fixes for ~10% of them. Cloud-Audit goes deep on each of its 94 checks, providing both CLI commands and Terraform code you can review before applying. Different philosophy - direct mutation vs reviewable IaC output.

Security Drift Detection: Comparing Scan Results

Do you know why change tracking is so important? I’ll describe a workflow for you; you might know this from experience or at least from observation. You run a security scan, get a report. Okay, that needs fixing too, so you implement the changes, and everything’s great. Three months later, it turns out someone gained access to one of the applications via SSH because one of the engineers had “temporarily” opened port 22 on 0.0.0.0/0 directly in the console and forgot to remove it.

IaC scanning (tfsec, checkov, trivy) catches errors in code configuration. Terraform module validation helps before deployment. However, it doesn’t catch what happens after deployment - console changes, ClickOps, manual security group edits, temporary exceptions that become permanent.

This is the gap that a differential scan fills. Run a scan today, run another tomorrow, and compare them:

cloud-audit scan --format json --output monday.json
# ... time passes ...
cloud-audit scan --format json --output tuesday.json
cloud-audit diff monday.json tuesday.json

Output:

Score: 54 -> 68 (+14)

Fixed (2):
  CRITICAL  aws-iam-001   root         Root account without MFA
  HIGH      aws-vpc-002   sg-abc123    SG open on port 22

New (1):
  HIGH      aws-rds-001   staging-db   RDS publicly accessible

Unchanged (8): ...

An exit code of 0 indicates no new findings (the situation has improved or remained unchanged). An exit code of 1 indicates a regression - something new has appeared or has worsened. Connect it to a cron job or a scheduled GitHub Actions workflow and you’ll be notified when your security posture deteriorates. You can see the full list of checks cloud-audit runs - from root MFA to OIDC trust policy validation - on the individual check pages.

How does Prowler handle this? Prowler’s open-source CLI does not have a standalone diff or comparison command. Scan comparison is available through the self-hosted Prowler App (open-source) or the hosted Prowler Cloud tier - both provide dashboards, historical trends, and delta filters. But if you’re using the free CLI only, you’d need to build your own diffing script around the JSON output.

Cloud-Audit’s diff command fills that gap in the free CLI space - it produces a standalone comparison report (markdown, JSON) with categorized results (new/fixed/changed/unchanged) and exit codes designed for CI gating. No dashboard, no platform - just two JSON files in, comparison out.

ScoutSuite doesn’t support drift tracking at all.

Attack Chains: From Flat Findings to Real Attack Paths

This is the feature that changed how I think about security scanning.

Most scanners produce a flat list of findings. “Security group open on port 22.” “IMDSv1 enabled.” “IAM role has admin policy.” Each finding on its own might be medium or high severity. But what happens when all three exist on the same EC2 instance?

An attacker reaches the instance through the open security group, queries IMDSv1 to steal the IAM role credentials, and those credentials have admin access. Three medium findings become a critical attack path leading to full account takeover.

This is what commercial CSPM tools like Wiz and Orca sell as “toxic combinations” or “attack path analysis.” Prowler also offers this through the Prowler App (open-source, Apache 2.0) - using Neo4j and Cartography to build a graph of your cloud resources and map privilege escalation paths. It’s a powerful approach, but it requires the Prowler App stack (self-hosted or via the hosted Prowler Cloud tier) plus a Neo4j instance.

As of v1.0, cloud-audit has 31 attack chain rules that correlate findings into exploitable multi-step attack paths. Each chain also includes an estimated breach cost range in USD, so you can prioritize by financial risk, not just severity:

cloud-audit scan

+---- Attack Chains (3 detected) -----------------------------------+
|                                                                    |
|  CRITICAL  Internet-Exposed Admin Instance                         |
|            i-0abc123 - public SG + admin IAM role                  |
|            > Attacker reaches EC2 > steals IMDS creds > admin      |
|            Risk: $180,000 - $490,000                               |
|            Fix: Restrict security group (effort: LOW)              |
|                                                                    |
|  CRITICAL  CI/CD to Admin Takeover                                 |
|            github-deploy - OIDC no sub + admin policy              |
|            > Any GitHub repo can assume admin AWS role              |
|            Fix: Add sub condition (effort: LOW)                    |
|                                                                    |
|  HIGH      Zero Security Visibility                                |
|            No CloudTrail + No GuardDuty + No Config                |
|            > Attackers operate completely undetected                |
|            Fix: Enable CloudTrail (effort: LOW)                    |
|                                                                    |
+--------------------------------------------------------------------+

The rules are based on the MITRE ATT&CK Cloud Matrix, Datadog’s pathfinding.cloud research, and the AWS CIRT Threat Catalog. They cover four tiers: internet exposure with privilege escalation, missing security controls, data protection gaps, and CI/CD pipeline risks.

How is this different from Prowler’s attack paths? Prowler’s graph-based analysis with Neo4j is more comprehensive - privilege escalation paths computed from a full resource relationship graph built by Cartography, with custom openCypher queries. But it requires running the Prowler App stack (self-hosted open-source or the hosted Prowler Cloud tier) plus a Neo4j database. Cloud-audit’s 31 rules run in the free CLI with zero infrastructure - pip install cloud-audit and you’re done.

To be clear about the limitation: cloud-audit correlates its own 94 checks with 31 predefined rules. Prowler App maps 78 AWS attack path queries across a full resource graph. Wiz and Orca correlate across hundreds of data sources including network reachability, identity graphs, and vulnerability databases. The scope is different at each level. But if you want attack path context without setting up a platform or paying for a subscription, cloud-audit is the only CLI tool that includes it out of the box.

For privilege escalation specifically: I ran cloud-audit, Prowler, Cloudsplaining, PMapper, and CloudFox against 57 documented IAM privesc paths. Coverage ranged from 7% to 93%. Full per-tool matrix and bias-free Bishop Fox subset analysis: 5 AWS IAM Privesc Scanners vs 57 Paths: Coverage from 7% to 93%.

Installation and Quick Start Commands

Prowler

pip install prowler
prowler aws

Prowler also supports Docker and has a pre-built AWS CloudFormation template for setting up the required IAM role.

For a focused scan:

# Run only CIS 1.5 checks
prowler aws --compliance cis_1.5_aws

# Specific services only
prowler aws --services iam s3 ec2

# Auto-remediate supported checks (55 across 17 AWS services - direct API calls)
prowler aws --check <check_id> --fixer

ScoutSuite

pip install scoutsuite
scout aws

This generates an interactive HTML report in scoutsuite-results/. Open scoutsuite-results/aws-123456789012.html in a browser.

Note: ScoutSuite has not been updated since May 2024. Installation may require pinning dependency versions on newer Python releases.

cloud-audit

pip install cloud-audit
cloud-audit scan

For remediation details:

# Show CLI + Terraform fixes
cloud-audit scan -R

# Export fixes as a script
cloud-audit scan --export-fixes fixes.sh

# HTML report
cloud-audit scan --format html --output report.html

# SARIF for GitHub Security tab
cloud-audit scan --format sarif --output results.sarif

All three tools use your default AWS credentials. They all need read-only access - the AWS-managed SecurityAudit policy works for all of them, though Prowler may need additional permissions for certain checks.

Both Prowler and cloud-audit ship MCP Servers for AI-assisted security workflows. Prowler’s MCP Server provides access to their security knowledge base (1,000+ checks and remediation scripts) without authentication, while app features like scan results and findings require a Prowler Cloud API key. Cloud-audit’s MCP Server gives full access to all features - scanning, findings, attack chains, remediation - without any API key or account:

# Add cloud-audit as an MCP server in Claude Code
claude mcp add cloud-audit -- uvx cloud-audit-mcp

This gives your AI agent six tools: scan_aws, get_findings, get_attack_chains, get_remediation, get_health_score, and list_checks. You can ask your AI assistant to scan your account, explain findings, or generate remediation code - all without leaving your editor.

Other AWS Security Scanners Worth Knowing

A few other tools worth knowing about:

Trivy - Aqua Security’s scanner covers containers, IaC, SBOM, and cloud accounts. It’s becoming a Swiss army knife for security scanning. Strong choice if you already use it for container scanning and want to add cloud checks.
Steampipe - Query your cloud infrastructure with SQL across 153 plugins and 2,000+ tables. Extremely flexible but requires writing or configuring queries. Great for ad-hoc investigations, less great for automated scanning pipelines.
AWS Security Hub - AWS’s native service with 430+ automated controls. Integrates with GuardDuty, Inspector, Macie. Free 30-day trial, then you pay per check evaluation. The right choice if you want continuous monitoring without managing any tooling.

Which AWS Security Scanner Should You Use?

Pick the tool that matches your actual need:

Need compliance evidence? Prowler. Nothing else in the open-source space matches its framework coverage.

Need a quick audit with actionable fixes? Cloud-Audit. 94 checks, each with a CLI command and Terraform code you can copy-paste.

Need to see how findings combine into attack paths? Both Prowler and cloud-audit offer this. Prowler’s approach is more powerful (graph-based with Neo4j + Cartography) but requires running the Prowler App stack (self-hosted or hosted Cloud tier). Cloud-audit’s 31 rules run in the free CLI with zero setup and include breach cost estimates in USD.

Need AI-assisted security workflows? Both tools offer MCP Servers. Prowler’s MCP provides access to their security knowledge base (1,000+ checks, remediation scripts) for free, with app features requiring an API key. Cloud-audit’s MCP lets you run full scans and query results directly from your editor - all features free.

Need to track security drift over time? Cloud-Audit’s diff command does this in the free CLI with CI-friendly exit codes. Prowler offers it through the self-hosted Prowler App (open-source) or the hosted Prowler Cloud tier.

Need multi-cloud? Prowler (AWS/Azure/GCP/K8s and more) or Trivy.

Need continuous monitoring? AWS Security Hub if you’re willing to pay, Prowler on a cron job if you’re not.

ScoutSuite? Hasn’t been updated since May 2024. Time to look elsewhere.

The tools are not mutually exclusive. Use what fits your workflow.

Quick Decision Matrix

Your situation	Best pick	Why
Compliance audit (SOC2, PCI-DSS, CIS)	Prowler	41 frameworks, structured evidence
Quick one-off security check	cloud-audit	94 checks, copy-paste CLI + Terraform fixes
CI/CD pipeline gating	cloud-audit	SARIF output, exit codes, fast scans
Multi-cloud (AWS + Azure + GCP)	Prowler or Trivy	cloud-audit is AWS only
Attack path analysis (enterprise)	Prowler App	Neo4j graph, 78 AWS attack path queries
Attack path analysis (free, no infra)	cloud-audit	31 CLI rules, zero setup, breach cost estimates
Security drift tracking	cloud-audit	Built-in `diff` command, CI-friendly
Container + cloud in one tool	Trivy	Single binary, all scan targets
Continuous monitoring (managed)	AWS Security Hub	430+ controls, native integrations

Want a professional review of your AWS security posture? I offer a free initial AWS security review that covers IAM, networking, encryption, and logging - no commitment required.