Cloud Custodian vs Prowler vs ScoutSuite: Which Cloud Security Tool in 2026?

Cloud security posture tools split into two real categories: ones that audit and report (Prowler, ScoutSuite) and ones that actively enforce and remediate (Cloud Custodian). Confusing the two is the most common mistake teams make picking between them — here is an honest comparison.

Quick Comparison

Cloud Custodian

Cloud Custodian is fundamentally different from the other two — it's not an auditor, it's a policy engine that continuously enforces rules and can take real remediation action.

# policy.yml — Cloud Custodian policy
policies:
  - name: terminate-unencrypted-ebs
    resource: ebs
    filters:
      - Encrypted: false
    actions:
      - type: notify
        to:
          - security-team@company.com
        subject: "Unencrypted EBS volume detected"
      - type: tag
        tags:
          non-compliant: "true"
 
  - name: stop-untagged-instances-after-24h
    resource: ec2
    filters:
      - "tag:Owner": absent
      - type: age
        days: 1
    actions:
      - stop

Cloud Custodian strengths:

• Genuinely continuous — runs on a schedule, enforcing policy in near-real-time rather than a point-in-time snapshot
• Real remediation actions built in (stop, tag, notify, delete, snapshot-then-delete) — not just a report to act on later
• Policy-as-code fits naturally into GitOps workflows — policies are YAML, version-controlled and reviewed like any other infra config

Cloud Custodian weaknesses:

• Not designed as a compliance-report generator — mapping to CIS/SOC2/PCI controls needs custom policy-writing, not built-in
• Steeper learning curve since you're writing enforcement logic, not just running a scan
• AWS support is the most mature; Azure/GCP policy coverage lags behind

When to use Cloud Custodian: You want automated, continuous enforcement of security/cost/compliance policies with real remediation — not just a periodic report.

Prowler

Prowler is the most compliance-framework-oriented of the three — it maps directly to CIS Benchmarks, SOC2, PCI-DSS, HIPAA, and more, out of the box.

prowler aws --compliance cis_2.0_aws --output-formats html,json,csv
prowler azure --compliance cis_3.0_azure
prowler kubernetes --compliance cis_1.8_k8s    # Prowler also covers K8s clusters

Prowler strengths:

• Best-in-class compliance framework mapping — if an auditor asks "are we CIS-compliant," Prowler's report is built for exactly that question
• Broadest scope of the three: AWS, Azure, GCP, Kubernetes, and even Microsoft 365
• Active open-source community, frequent rule updates as compliance frameworks evolve
• Good CI integration for pre-deployment compliance gates

Prowler weaknesses:

• No built-in remediation — findings need a separate process (manual or Cloud Custodian) to actually fix
• Point-in-time by default — needs external scheduling for continuous coverage
• Large finding volume on a first run can be overwhelming without prioritization tooling on top

When to use Prowler: You need compliance-framework-mapped audit reports for auditors or certifications, and can pair it with a separate remediation process.

ScoutSuite

ScoutSuite focuses on producing a clear, visual, browsable security posture report — its interactive HTML output is the most reviewer-friendly of the three.

scout aws --report-dir ./scoutsuite-report
scout gcp --report-dir ./scoutsuite-report
# Generates an interactive HTML dashboard, not just a flat report file

ScoutSuite strengths:

• The interactive HTML report is genuinely the easiest of the three to browse and share with non-security stakeholders
• Good multi-cloud coverage including Alibaba Cloud, which the others don't cover
• Clear severity grouping and rule explanations make it approachable for teams newer to cloud security review

ScoutSuite weaknesses:

• Less actively maintained release cadence than Prowler in recent years
• No compliance framework mapping as deep as Prowler's — more of a general security review than an audit-ready compliance report
• No remediation capability, same as Prowler

When to use ScoutSuite: You want a clear, visual, easy-to-share security posture snapshot for internal review rather than a formal compliance audit deliverable.

The Honest Verdict

Want ongoing automated enforcement with real remediation: Cloud Custodian. It's the only one of the three that actually fixes things, not just reports them.

Need compliance-framework-mapped audit reports for certifications: Prowler. The CIS/SOC2/PCI mapping is exactly what an auditor wants to see.

Want an approachable, visual security review for internal stakeholders: ScoutSuite. Best report UX of the three for non-security audiences.

Most mature security postures run more than one: Prowler or ScoutSuite for periodic audits and compliance reporting, Cloud Custodian running continuously for actual enforcement between those audits — the audit tools tell you what's wrong, Custodian is what keeps it from staying wrong.

More cloud security tooling? Read our Software supply chain security: SBOM and SLSA guide and Steampipe cloud security posture review.