Open Source Vulnerability Scanners -- Tenable Alternatives
Open-source vulnerability scanners provide cost-effective, transparent alternatives to Tenable for organizations that want vulnerability detection without commercial licensing costs. These tools give security teams full control over scanning logic, allow deep customization through community-contributed plugins and templates, and support self-hosted deployments that keep scan data under organizational control. They are ideal for teams with security engineering expertise that want to build custom scanning workflows or operate on constrained budgets.
Free (open source) / Greenbone Enterprise appliances from $5,000/year
The most comprehensive open-source vulnerability scanner with over 100,000 NVTs covering CVEs, misconfigurations, and compliance checks. Best for organizations wanting a traditional network vulnerability scanner without licensing costs, especially those with Linux administration expertise to deploy and maintain the platform.
Free (open source) / ProjectDiscovery Cloud Platform from $100/month
The fastest and most customizable open-source scanning engine with YAML-based templates and massive community contribution. Best for security engineers, DevSecOps teams, and researchers who need a lightweight, pipeline-friendly scanner with rapid coverage of emerging vulnerabilities.
The most widely used open-source vulnerability scanner with 100,000+ network vulnerability tests
Free (open source) / Greenbone Enterprise appliances from $5,000/year
Security teams wanting a free, open-source vulnerability scanner with no licensing costs and full customization control
Fast, template-based open-source vulnerability scanner with 8,000+ community-contributed detection templates
Free (open source) / ProjectDiscovery Cloud Platform from $100/month
Security teams and researchers wanting a fast, customizable, template-driven vulnerability scanner for web and infrastructure testing
Compare all 2 Tenable alternatives side-by-side across pricing, deployment, and key capabilities.
| Feature | Greenbone OpenVAS 4/5 | Nuclei 4.3/5 |
|---|---|---|
| Pricing Model | Open source with commercial appliance options | Open source with optional cloud platform |
| Open Source | + | + |
| Cloud-Hosted | -- | + |
| Self-Hosted | + | + |
| Best For | Security teams wanting a free, open-source vulnerability scanner with no licensing costs and full customization control | Security teams and researchers wanting a fast, customizable, template-driven vulnerability scanner for web and infrastructure testing |
| Key Features |
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| Website | Visit | Visit |
For basic vulnerability detection, yes. Both OpenVAS and Nuclei can identify known CVEs and misconfigurations across network and web assets. However, Tenable provides significantly more than just a scanning engine — it includes asset inventory, risk-based prioritization with VPR scoring, compliance benchmarks (CIS, DISA STIG, PCI DSS), remediation tracking, executive reporting, and enterprise support. Open-source scanners are best used as complementary tools or as primary scanners for organizations with the expertise to build vulnerability management workflows around raw scan output.
Greenbone OpenVAS has broader traditional vulnerability coverage with over 100,000 NVTs that include authenticated scanning, compliance checks, and deep network service assessment. Nuclei excels at web application and infrastructure vulnerability detection with over 8,000 templates that are rapidly updated by the community. For comprehensive network vulnerability scanning similar to Nessus, OpenVAS is the closer match. For fast, targeted web and infrastructure testing, Nuclei is superior.
Choose OpenVAS if you need a traditional network vulnerability scanner with authenticated scanning, compliance checks, and a web interface for managing scans and reports. Choose Nuclei if you need a fast, CLI-based scanner for CI/CD pipeline integration, custom template authoring, or security research. Many teams use both — OpenVAS for scheduled infrastructure scanning and Nuclei for targeted web application and emerging vulnerability detection.
While open-source scanners have zero licensing costs, they require engineering time for deployment, configuration, maintenance, and update management. OpenVAS requires a dedicated Linux server, database configuration, and ongoing NVT feed updates. Nuclei requires less infrastructure but needs expertise to write custom templates and build reporting workflows. Budget 10-20 hours per month for maintaining an open-source scanning program at moderate scale. For organizations where engineering time is expensive, Tenable's managed platform may deliver lower total cost of ownership.
The most widely used open-source vulnerability scanner with 100,000+ network vulnerability tests
ComparisonFast, template-based open-source vulnerability scanner with 8,000+ community-contributed detection templates
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