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Active Directory, security & utilities

Nessus (Tenable)

Widely used vulnerability scanner — free Essentials for up to 16 IPs.

freemiumdesktop

Reviewed by Giuseppe Tommaso Curella, Infrastructure & network engineer Updated 2026-11-05

Official site www.tenable.com

Independent reference — this page is a review. Nessus (Tenable) is downloaded from the vendor’s official site, not from here.

PlatformsWindows/Linux/macOS (local web UI on port 8834)
LicenceFreemium — Essentials free (16 IPs)
PriceEssentials free; Professional from ~$4,390/yr
SectionActive Directory, security & utilities
Updated2026-11-05

What it is

Widely used for vulnerability scanning, it probes servers, network gear and applications for known vulnerabilities and misconfigurations, surfacing unpatched systems and weak passwords. The free Essentials edition covers 16 addresses.

Problems it closes

  • You need to know which systems carry known vulnerabilities and misconfigurations.
  • Servers and network gear need regular authenticated vulnerability scans.
  • A small environment wants a free but credible scanning option.

How administrators run it

  • Install it and scan hosts, using authenticated scans when you need depth.
  • Sort findings by severity and chase the remediation through.
  • Lean on free Essentials for up to 16 IPs; step up to Professional for more.
Nessus vulnerability scan dashboard
Screenshot: docs.tenable.com (vendor, proprietary).

Strengths & trade-offs

Strengths

  • Extensive, well-maintained vulnerability checks.
  • There’s a free Essentials tier.
  • Reports are clear and actionable.

Trade-offs

  • Professional is a yearly subscription.
  • Essentials stops at 16 IP addresses.

Common questions

Is there a free version?

Yes — Nessus Essentials, for up to 16 IP addresses.

Does it fix the vulnerabilities?

No. It finds and prioritises them; the fixing is on you.

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