01 · Product name
Security Onion
Free NSM platform. Current page says 3.3.0.
Published by Security Onion Solutions, LLC.
In short
Security Onion is the free network-security monitoring platform from Security Onion Solutions. On 21 Oct 2026 securityonion.net redirected to securityonionsolutions.com, and the software page said the latest version is 3.3.0. The documentation index opened at docs.securityonion.net/en/2.4/ and is titled for the 2.4 docs. Those two version strings stay apart. The GitHub SPDX field was NOASSERTION. The repository description says the platform is free and open. The software page says it has been downloaded over 2 million times. A sensor is for a network you are allowed to watch.
Product pricing strategy
02
Free
The software page says the platform is free and open, and the GitHub description says the same. No dollar price for the 3.3.0 download, the cloud images, or Pro was printed on the software page or the 2.4 docs index opened 21 Oct 2026. The company site says buying products and services funds development, and it points Pro and Onion AI at a sales contact. A sales contact is not a number. This listing does not invent a Pro seat price. The over 2 million downloads sentence is the software page's counter. The 2021 history line of 2+ million is an older milestone on the company homepage. Neither counter is a fee. Cloud images on Amazon, Azure, and Google Cloud can create a bill with those vendors. That bill is not printed here.
Utility and features
03
The software page says Security Onion is a free and open platform for network visibility, host visibility, intrusion-detection honeypots, log management, and case management. It names Suricata for signatures, a choice of Zeek or Suricata for protocol metadata and file extraction, Suricata PCAP, Strelka for file analysis, and the Elastic Agent with osquery and Elastic Fleet for hosts. OpenCanary is the honeypot it names. The same page says the latest version is 3.3.0 and that Security Onion has been downloaded over 2 million times. The history block on the company homepage lists a 2021 milestone of 2+ million downloads and a 2026 line, Security Onion 3. The 3.3.0 string is the software page's current version. The 2021 line is a history milestone.
- Software page says 3.3.0. https://securityonionsolutions.com/software/ printed Latest version: 3.3.0 on 21 Oct 2026.
- Docs opened on 2.4. docs.securityonion.net/en/2.4/ is titled Security Onion Documentation 2.4. That string is not edited into 3.3.0.
- SPDX is NOASSERTION. The GitHub license field was NOASSERTION. The description says the platform is free and open. Both stay.
The docs URL that this review opened is https://docs.securityonion.net/en/2.4/. The page title is Security Onion Documentation 2.4, copyright 2026. Do not rename that tree 3.3.0. The GitHub API for Security-Onion-Solutions/securityonion on 21 Oct 2026 reported 4,936 stars and 682 forks, pushed 2026-10-19, and license SPDX NOASSERTION. The description field says it is free and open and names osquery, CyberChef, Elasticsearch, Logstash, Kibana, Suricata, and Zeek. NOASSERTION stays the license field. Pro, Onion AI, and local-model support are named on the company site. No dollar price for Pro was on the software page.
- 1
Follow 3.3.0 docs when you installed 3.3.0. Do not paste a step from the 2.4 tree onto that grid without checking it.
- 2
Quote NOASSERTION as the license field, and quote free and open as the description's words.
- 3
Point a sensor only at a network you are allowed to monitor. The platform does not grant that permission.
Caveats
04
3.3.0 is the software page. The docs index this review opened is the 2.4 tree. Using a 2.4 instruction on a 3.3.0 grid, or the reverse, is how a step goes missing. Quote the page you followed.
The SPDX field is NOASSERTION. The words free and open are the software page and the GitHub description. They do not fill the license field. Zeek and Suricata are included tools with their own pages in this directory. CyberChef is named in the GitHub description and has its own listing. A Security Onion grid collects packets and logs from networks you are allowed to sensor. It is not an OSINT desktop, and the category is the nearest existing one. No default password was printed on the software page. Do not import one from another distro.
Screenshots
05
Potential use cases
06
- A grid is about to be documented as one version. On 21 Oct 2026 the software page said the latest version is 3.3.0. The docs index this review opened, docs.securityonion.net/en/2.4/, is titled Security Onion Documentation 2.4. Follow the tree that matches the install. The software page also says the platform has been downloaded over 2 million times.
- The license line is about to be cleaned up. The GitHub API reported SPDX NOASSERTION, 4,936 stars, 682 forks, and a push on 19 Oct 2026. The repository description and the software page both say the platform is free and open. NOASSERTION stays the field. No Pro dollar price was printed on the software page.
- A sensor deploy is about to be treated as an OSINT desktop. The software page describes Suricata, Zeek or Suricata metadata, PCAP, Strelka, Elastic Agent, and OpenCanary for networks and hosts you monitor. The category in this directory is the nearest one. The job is network security monitoring on a network you are allowed to watch.
Hard cases
The case where the first result is easy to over-read.
A 2.4 step is run on 3.3.0
The software page's current version and the docs tree this review opened are different strings. Pasting a 2.4 command onto a 3.3.0 manager, or calling the 2.4 manual the 3.3.0 manual, invents a sentence. Cite the URL you actually followed.
Questions
Is Security Onion free?
The software page says it is free and open. The GitHub description says the same. No dollar price for the download or for Pro was printed on the pages opened 21 Oct 2026. The SPDX field was NOASSERTION.
Is the current version 2.4 or 3.3.0?
The software page said 3.3.0. The documentation index opened at /en/2.4/ is titled for 2.4. Quote the page you used. Do not merge the two strings.
Citations
07
Titled sources. These public pages are what the quotes on this listing come from.
Product
Security Onion software
https://securityonionsolutions.com/software/Documentation
Security Onion 2.4 documentation
https://docs.securityonion.net/en/2.4/Documentation
Security Onion repository
https://github.com/Security-Onion-Solutions/securityonion