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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 718

Nessus

What is Nessus?

NessusA commercial vulnerability scanner from Tenable that identifies missing patches, misconfigurations, and exposed services across networks, endpoints, and cloud workloads.


Nessus is one of the most widely deployed vulnerability scanners, originally released as open source by Renaud Deraison in 1998 and now developed and sold by Tenable. It performs authenticated and unauthenticated scans against operating systems, databases, network devices, web servers, containers, and cloud workloads, mapping findings to CVE, CVSS, EPSS, and compliance benchmarks such as CIS and PCI DSS. Security teams use Nessus for routine vulnerability management, pre-engagement reconnaissance during penetration tests, and as a data source for risk-based prioritization tools. Like any scanner, it can cause service disruption and must be scoped, throttled, and authorized before use.

Examples

  1. 01

    Running an authenticated Nessus scan against a Windows fleet to identify missing patches and risky services.

  2. 02

    Exporting Nessus findings to a vulnerability management platform for ticketing and SLA tracking.

Frequently asked questions

What is Nessus?

A commercial vulnerability scanner from Tenable that identifies missing patches, misconfigurations, and exposed services across networks, endpoints, and cloud workloads. It belongs to the Defense & Operations category of cybersecurity.

What does Nessus mean?

A commercial vulnerability scanner from Tenable that identifies missing patches, misconfigurations, and exposed services across networks, endpoints, and cloud workloads.

How does Nessus work?

Nessus is one of the most widely deployed vulnerability scanners, originally released as open source by Renaud Deraison in 1998 and now developed and sold by Tenable. It performs authenticated and unauthenticated scans against operating systems, databases, network devices, web servers, containers, and cloud workloads, mapping findings to CVE, CVSS, EPSS, and compliance benchmarks such as CIS and PCI DSS. Security teams use Nessus for routine vulnerability management, pre-engagement reconnaissance during penetration tests, and as a data source for risk-based prioritization tools. Like any scanner, it can cause service disruption and must be scoped, throttled, and authorized before use.

How do you defend against Nessus?

Defences for Nessus typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for Nessus?

Common alternative names include: Nessus Professional, Tenable Nessus.

Related terms

See also