OpenVAS (Open Vulnerability Assessment System, originally known as GNessUs) is a software framework of several services and tools offering vulnerability scanning and vulnerability management.

All OpenVAS products are free software, and most components are licensed under the GNU General Public License (GPL). Plugins for OpenVAS are written in the Nessus Attack Scripting Language, NASL.

OpenVAS is an open-source alternative to commercial tools such as Nessus. OpenVAS also performs network vulnerability scans.

OpenVAS is accessed through a web interface https://127.0.0.1:9392.