Greenbone OpenVAS vs Tenable

Greenbone OpenVAS is the leading open-source alternative to Tenable, providing free vulnerability scanning with over 100,000 NVTs. While it cannot match Tenable's scanning speed, plugin breadth, or advanced features like attack path analysis and cloud-native scanning, OpenVAS eliminates licensing costs entirely and provides full transparency into scanning logic. It is best suited for organizations with strong Linux expertise that need a cost-effective scanning foundation.

Choose Greenbone OpenVAS if you need a free, open-source vulnerability scanner and have the Linux expertise to deploy and maintain it. Choose Tenable if you need enterprise-grade scanning speed, cloud-native coverage, risk-based prioritization, and professional support.

Tenable starts at Nessus Professional from $3,990/year / Tenable.io from $2,275/year (65 assets) / Enterprise custom pricing (per-asset (annual subscription)). Greenbone OpenVAS starts at Free (open source) / Greenbone Enterprise appliances from $5,000/year (open source with commercial appliance options). As always, the sticker price only tells part of the story. Factor in add-ons, implementation costs, and what's actually included at each tier.

It depends on how deeply Greenbone OpenVAS is embedded in your stack. Most teams run both in parallel for a few weeks before cutting over. Check whether Tenable supports importing your existing configs or policies. That's usually the biggest time sink.