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

It depends on your use case. Prowler is the most comprehensive with 584 AWS checks (1,100+ total across all providers) and full CIS benchmark coverage - best for enterprise compliance audits. cloud-audit is best for quick one-off audits and CI/CD gating, with 45 checks that each include copy-paste remediation (AWS CLI + Terraform). 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.

Is Prowler free or paid?

Prowler's open-source CLI is free under Apache 2.0 with all 584 AWS checks and 55 auto-fixers included. Scan comparison and dashboards require the paid Prowler Cloud platform or self-hosted Prowler App. cloud-audit is also free (MIT license) with all features included - diff command, remediation output, SARIF - there is no paid tier.

Prowler vs ScoutSuite vs cloud-audit [2026]

As of 2026, we can find many open source tools that scan AWS accounts for potentially unsafe configurations. Anyone who cares about the security of their AWS infrastructure has likely already searched for such tools and stumbled upon Prowler, ScoutSuite, Trivy, Steampipe, and a few others while browsing “best tools” rankings.

I’ve used most of them myself. I’ve seen both pros and cons. This prompted me to dedicate the time to creating my own scanner. In this post, I’d like to compare three CLI-based scanners - Prowler, ScoutSuite, and Cloud-Audit (my tool). I’ll try to be as objective as possible, but I’ll let the comparison speak for itself.

Each solves different problems at different scales. I’ll point out where each scanner fits and where it doesn’t.

AWS Security Scanner Comparison Table

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

Feature	Prowler	ScoutSuite	cloud-audit
Checks	584 AWS (1,100+ total)	~200	45
Cloud providers	AWS, Azure, GCP, K8s + more	AWS, Azure, GCP, OCI	AWS only
CIS Benchmark mapping	Full (41 frameworks for AWS)	Partial	16 controls
Remediation	Docs links + `--fixer` (55 auto-fixers / 584 checks)	None	CLI + Terraform for every finding
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
Last release	Active (weekly)	May 2024	March 2026 (v0.8.0)
Stars (GitHub)	13.3k+	7.5k+	14
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 45 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.

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 (CloudTrail, GuardDuty, KMS, IAM, and more). These fixers work by making direct AWS API calls to change your infrastructure. That covers about 9.4% of Prowler’s 584 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 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 45 checks. Prowler covers 584 for AWS alone. If you require a broad scope, Prowler is a better choice.

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 out of 584 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 (584 AWS checks) with direct API fixes for ~9% of them. Cloud-Audit goes deep on each of its 45 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.

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 paid Prowler Cloud platform and the self-hosted Prowler App - 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.

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 of 584 - 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.

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. 45 checks, each with a CLI command and Terraform code you can copy-paste.

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 their paid platform or self-hosted App.

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.