Security Onion 2.4.200 now available with Major Improvements for our Onion AI Assistant!

Security Onion 2.4.200 is now available and includes several new features, updated components, and many quality of life improvements! 

For Security Onion Pro customers, we've made major improvements for our popular new Onion AI Assistant!

Onion AI is a huge leap forward in leveraging AI to assist you in triaging alerts, working incidents, and tuning your deployment!

Here are some of the improvements for Onion AI in this release:

• make Onion AI more accurate and curious
• add tool for creating / updating / disabling / enabling detections
• escalate to existing case
• auto compact context support
• additional UI metrics
• add option to use EU region instead of US for Onion AI
• add QWEN 235B as a lower cost option for an Onion AI model (please note that this model was trained in China but is hosted in your local AWS region and no data is logged)

https://docs.securityonion.net/en/2.4/assistant.html

IDSTools Replacement

For the last few years, we've used IDSTools to manage NIDS rulesets. In this release, we've removed IDSTools and moved this functionality into Security Onion Console. If you use the standard ETOPEN ruleset, then all migration should happen automatically. 

WARNING! If you have any custom Suricata rulesets, then all Suricata detection syncing will be blocked. For more information and required steps, see the Sync Block section of the documentation:

https://docs.securityonion.net/en/2.4/nids.html#syncblock

We highly recommend that you test this on a test deployment before you deploy to production!

Resolved Security Issue

On 12/14/2025, we were notified of a Remote Code Execution (RCE) vulnerability under certain circumstances. When joining a node to a distributed deployment, a file called install.txt is transferred from the node to the manager and then processed. An attacker can leverage this processing to achieve remote code execution on the manager. To do so, they must first have root access to the node to modify install.txt since it is only writable by root by default. If this is a new node that has not connected to the manager before, then it would be blocked by the manager's firewall by default. Allowing the traffic through the manager's firewall would require either root access to the manager or superuser rights in SOC. Once the traffic is allowed through, the salt minion running on the new node would have to be accepted by the manager which also requires superuser rights in SOC.

The fix for this issue is to ignore control characters in the install.txt file and that has been implemented in this release.

Timeline

12/14/2025 - responsible disclosure

12/15/2025 - merged fix

12/16/2025 - Security Onion 2.4.200 released including fix

Thanks to Ashlen for the responsible disclosure!

Updated Components

This release updates several components including:

• Saltstack to 3006.16
• Strelka to 1.0.1
• Suricata to 8.0.2
• Zeek to 8.0.4

With the upgrade to Suricata 8, our recommended full packet capture utility is now Suricata. Stenographer will be removed next year so if you haven't already transitioned from Stenographer to Suricata PCAP then now is the time to do so:

https://docs.securityonion.net/en/2.4/suricata.html#switching-pcap-from-stenographer-to-suricata

Release Notes

There are many more features and fixes included in this release! For a complete list of all changes, please see the Release Notes:

https://docs.securityonion.net/en/2.4/release-notes.html#changes

Known Issues

If you haven't viewed cases in a while, escalating from Onion AI to an existing case will fail.

For a list of known issues, please see:

https://docs.securityonion.net/en/2.4/release-notes.html#known-issues

About Security Onion

Security Onion is a free and open platform built by defenders for defenders. It includes network visibility, host visibility, intrusion detection honeypots, log management, and case management. 

For network visibility, we offer signature based detection via Suricata, rich protocol metadata and file extraction using your choice of either Zeek or Suricata, full packet capture, and file analysis. For host visibility, we offer the Elastic Agent which provides data collection, live queries via osquery, and centralized management using Elastic Fleet. Intrusion detection honeypots based on OpenCanary can be added to your deployment for even more enterprise visibility. All of these logs flow into Elasticsearch and we’ve built our own user interfaces for alerts, dashboards, threat hunting, case management, and grid management. 

Security Onion has been downloaded over 2 million times and is being used by security teams around the world to monitor and defend their enterprises. Our easy-to-use Setup wizard allows you to build a distributed grid for your enterprise in minutes!

Documentation

You can find our online documentation here:

https://docs.securityonion.net/en/2.4/

Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.

New Installations

If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:

https://docs.securityonion.net/en/2.4/first-time-users.html

Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:

https://docs.securityonion.net/en/2.4/architecture.html

Existing 2.4 Installations

If you have an existing Security Onion 2.4 installation, you can update to the latest version using soup:

https://docs.securityonion.net/en/2.4/soup.html

Before updating your production deployment, we highly recommend testing the upgrade process on a test deployment that closely matches your production deployment if possible. This is especially important for releases that update components like Salt and Elastic.

2.3 EOL

As a reminder, Security Onion 2.3 reached End Of Life (EOL) on April 6, 2024:

https://blog.securityonion.net/2023/10/6-month-eol-notice-for-security-onion-23.html

Thanks

Lots of love went into this release!

Special thanks to all our folks working so hard to make this release happen!

• Josh Brower
• Jason Ertel
• Corey Ogburn
• Josh Patterson
• Mike Reeves
• Jorge Reyes
• Matthew Wright

Questions, Problems, and Feedback

If you have any questions or problems, please create a new Discussion at:

https://securityonion.net/discuss

Security Onion Pro

We recently celebrated 10 years in business by announcing Security Onion Pro:

https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html

Security Onion Pro includes many enterprise features that folks have been asking for:

• Active Query Management
• External API
• Open ID Connect (OIDC)
• Data at Rest Encryption
• FIPS for the OS
• DoD STIG for the OS
• External Notifications in SOC
• Time Tracking inside of Cases
• Guaranteed Message Delivery
• Manager of Managers
• MCP Server
• Security Onion App for Splunk
• Hypervisor
• Reports
• Onion AI Assistant

You can read more about these enterprise features at:

https://securityonion.com/pro

Training

Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!

https://securityonion.net/training

Security Onion Solutions Hardware Appliances

We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!

https://securityonion.com/hardware

Cloud Installations

For new Security Onion 2 installations in the cloud, this new version will soon be available on the AWS, Azure, and GCP marketplaces!

AWS Marketplace and Documentation:

https://securityonion.net/aws/?ref=_ptnr_soc_blog_251216

https://docs.securityonion.net/en/2.4/cloud-amazon.html

Azure Marketplace and documentation:

https://securityonion.net/azure

https://docs.securityonion.net/en/2.4/cloud-azure.html

GCP Marketplace and documentation:

https://securityonion.net/google

https://docs.securityonion.net/en/2.4/cloud-google.html

Security Onion 2.4.190 now available including Onion AI Assistant for Pro Customers!

Security Onion 2.4.190 is now available and includes several new features, updated components, and many quality of life improvements! 

For Security Onion Pro customers, we've improved our hypervisor feature and added the new Onion AI Assistant!

Updated Components

This release updates several components including:

• ATT&CK Navigator
• ElastAlert
• Elastic Stack
• Golang
• Nginx
• Redis
• Telegraf
• Zeek
  
  

The Elastic and Redis updates resolve security issues so we highly recommend upgrading.

Security Onion Pro Feature: Hypervisor

In the recent 2.4.170 release, we added a new hypervisor feature for Security Onion Pro customers and then improved it in 2.4.180. This release continues to iterate on the Hypervisor feature making it even more powerful! For more information about the Hypervisor feature, please see:

https://docs.securityonion.net/en/2.4/hypervisor.html

Security Onion Pro Feature: Onion AI Assistant

Onion AI is a huge leap forward in leveraging AI to assist you in triaging alerts and working incidents!

https://docs.securityonion.net/en/2.4/assistant.html

Release Notes

There are many more features and fixes included in this release! For a complete list of all changes, please see the Release Notes:

https://docs.securityonion.net/en/2.4/release-notes.html#changes

Known Issues

For a list of known issues, please see:

https://docs.securityonion.net/en/2.4/release-notes.html#known-issues

About Security Onion

Security Onion is a free and open platform built by defenders for defenders. It includes network visibility, host visibility, intrusion detection honeypots, log management, and case management. 

For network visibility, we offer signature based detection via Suricata, rich protocol metadata and file extraction using your choice of either Zeek or Suricata, full packet capture, and file analysis. For host visibility, we offer the Elastic Agent which provides data collection, live queries via osquery, and centralized management using Elastic Fleet. Intrusion detection honeypots based on OpenCanary can be added to your deployment for even more enterprise visibility. All of these logs flow into Elasticsearch and we’ve built our own user interfaces for alerts, dashboards, threat hunting, case management, and grid management. 

Security Onion has been downloaded over 2 million times and is being used by security teams around the world to monitor and defend their enterprises. Our easy-to-use Setup wizard allows you to build a distributed grid for your enterprise in minutes!

Documentation

You can find our online documentation here:

https://docs.securityonion.net/en/2.4/

Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.

New Installations

If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:

https://docs.securityonion.net/en/2.4/first-time-users.html

Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:

https://docs.securityonion.net/en/2.4/architecture.html

Existing 2.4 Installations

If you have an existing Security Onion 2.4 installation, you can update to the latest version using soup:

https://docs.securityonion.net/en/2.4/soup.html

Before updating your production deployment, we highly recommend testing the upgrade process on a test deployment that closely matches your production deployment if possible. This is especially important for releases that update components like Salt and Elastic.

2.3 EOL

As a reminder, Security Onion 2.3 reached End Of Life (EOL) on April 6, 2024:

https://blog.securityonion.net/2023/10/6-month-eol-notice-for-security-onion-23.html

Thanks

Lots of love went into this release!

Special thanks to all our folks working so hard to make this release happen!

• Josh Brower
• Jason Ertel
• Corey Ogburn
• Josh Patterson
• Mike Reeves
• Jorge Reyes
• Matthew Wright

Questions, Problems, and Feedback

If you have any questions or problems, please create a new Discussion at:

https://securityonion.net/discuss

Security Onion Pro

We recently celebrated 10 years in business by announcing Security Onion Pro:

https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html

Security Onion Pro includes many enterprise features that folks have been asking for:

• Active Query Management
• External API
• Open ID Connect (OIDC)
• Data at Rest Encryption
• FIPS for the OS
• DoD STIG for the OS
• External Notifications in SOC
• Time Tracking inside of Cases
• Guaranteed Message Delivery
• Manager of Managers
• MCP Server
• Security Onion App for Splunk
• Hypervisor
• Reports
• Onion AI Assistant

You can read more about these enterprise features at:

https://securityonion.com/pro

Training

Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!

https://securityonion.net/training

Security Onion Solutions Hardware Appliances

We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!

https://securityonion.com/hardware

Cloud Installations

For new Security Onion 2 installations in the cloud, this new version will soon be available on the AWS, Azure, and GCP marketplaces!

AWS Marketplace and Documentation:

https://securityonion.net/aws/?ref=_ptnr_soc_blog_250917

https://docs.securityonion.net/en/2.4/cloud-amazon.html

Azure Marketplace and documentation:

https://securityonion.net/azure

https://docs.securityonion.net/en/2.4/cloud-azure.html

GCP Marketplace and documentation:

https://securityonion.net/google

https://docs.securityonion.net/en/2.4/cloud-google.html

Security Onion 2.4.160 now available including Playbooks, Guided Analysis, MCP Server, and more!

Security Onion 2.4.160 is now available and includes Playbooks and Guided Analysis to help you more quickly triage and respond to alerts! Security Onion Pro customers will also have access to our new MCP Server and Security Onion App for Splunk!

Playbooks and Guided Analysis

Have you ever had an alert and were unsure of what to do next? In this release, when you expand an alert you'll see a new tab called Guided Analysis. This leverages Playbooks to show you plays associated with the alert. These plays include questions which help guide your investigation. Each question has an associated query and the results of that query will be automatically displayed to help you answer the question. This makes you faster and more efficient than ever before!

If you'd like to see this in action, take a look at the Sneak Peek video we released last week:

https://www.youtube.com/watch?v=SLGRB3PxB-o

Playbooks implements the the Human-Centered Investigation Playbook, a standard developed by Chris Sanders. You can read more about it here:

https://chrissanders.org/2025/06/human-centered-playbooks/

https://chrissanders.org/hcip/Human-Centered%20Playbook%20Standard%20v1.0.pdf

This release includes a number of hand-written playbooks that are used at the detection engine (NIDS | Sigma | YARA) and category (eg "ET MALWARE") level. We have also used AI to generate individual Playbooks for all ETOPEN NIDS rules (58k). If you see an issue with one, please reach out and let us know.

MCP Server

Enterprise customers utilizing their own AI/LLM platform can now interface that platform directly to their Security Onion grid by utilizing the Security Onion Model Context Protocol (MCP) server.

The MCP server gives AI the ability to query alerts, playbooks, events, etc. which provides the LLM with additional information needed to make informed decisions. This functionality utilizes the Security Onion Connect API, so a valid Security Onion Pro license is required.

For more information, please see the documentation:

https://docs.securityonion.net/en/2.4/mcp.html

Security Onion App for Splunk

If you use Splunk, then you may be interested in the new Security Onion App for Splunk. This app uses the Security Onion Connect API to allow Splunk to integrate into our platform. Since it uses the Connect API, a valid Security Onion Pro license is required.

Please note that the Security Onion App for Splunk is not officially supported at this time.

You can read more in our documentation:

https://docs.securityonion.net/en/2.4/splunk.html

Release Notes

There are many more features and fixes included in this release! For a complete list of all changes, please see the Release Notes:

https://docs.securityonion.net/en/2.4/release-notes.html#changes

Known Issues

For a list of known issues, please see:

https://docs.securityonion.net/en/2.4/release-notes.html#known-issues

About Security Onion

Security Onion is a free and open platform built by defenders for defenders. It includes network visibility, host visibility, intrusion detection honeypots, log management, and case management. 

For network visibility, we offer signature based detection via Suricata, rich protocol metadata and file extraction using your choice of either Zeek or Suricata, full packet capture, and file analysis. For host visibility, we offer the Elastic Agent which provides data collection, live queries via osquery, and centralized management using Elastic Fleet. Intrusion detection honeypots based on OpenCanary can be added to your deployment for even more enterprise visibility. All of these logs flow into Elasticsearch and we’ve built our own user interfaces for alerts, dashboards, threat hunting, case management, and grid management. 

Security Onion has been downloaded over 2 million times and is being used by security teams around the world to monitor and defend their enterprises. Our easy-to-use Setup wizard allows you to build a distributed grid for your enterprise in minutes!

Documentation

You can find our online documentation here:

https://docs.securityonion.net/en/2.4/

Documentation is always a work in progress. If you find documentation that needs to be updated, please let us know as described in the Feedback section below.

New Installations

If this is your first time installing Security Onion 2.4, then we highly recommend starting with an IMPORT installation as shown at:

https://docs.securityonion.net/en/2.4/first-time-users.html

Once you’re comfortable with your IMPORT installation, then you can move on to more advanced installations as shown at:

https://docs.securityonion.net/en/2.4/architecture.html

Existing 2.4 Installations

If you have an existing Security Onion 2.4 installation, you can update to the latest version using soup:

https://docs.securityonion.net/en/2.4/soup.html

Before updating your production deployment, we highly recommend testing the upgrade process on a test deployment that closely matches your production deployment if possible. This is especially important for releases that update components like Salt and Elastic.

2.3 EOL

As a reminder, Security Onion 2.3 reached End Of Life (EOL) on April 6, 2024:

https://blog.securityonion.net/2023/10/6-month-eol-notice-for-security-onion-23.html

Thanks

Lots of love went into this release!

Special thanks to all our folks working so hard to make this release happen!

• Josh Brower
• Jason Ertel
• Corey Ogburn
• Josh Patterson
• Mike Reeves
• Jorge Reyes
• Matthew Wright

Questions, Problems, and Feedback

If you have any questions or problems relating to Security Onion 2.4, please use the 2.4 category at our Discussions site:

https://github.com/Security-Onion-Solutions/securityonion/discussions/categories/2-4

Security Onion Pro

We recently celebrated 10 years in business by announcing Security Onion Pro:

https://blog.securityonion.net/2024/07/celebrating-10-years-of-security-onion.html

Security Onion Pro includes many enterprise features that folks have been asking for:

• Active Query Management
• External API
• Open ID Connect (OIDC)
• Data at Rest Encryption
• FIPS for the OS
• DoD STIG for the OS
• External Notifications in SOC
• Time Tracking inside of Cases
• Guaranteed Message Delivery
• Manager of Managers
• MCP Server
• Security Onion App for Splunk

You can read more about these enterprise features at:

https://securityonion.com/pro

Training

Need training? Start with our free Security Onion Essentials training and then take a look at some of our other official Security Onion training!

https://securityonion.net/training

Security Onion Solutions Hardware Appliances

We know Security Onion's hardware needs, and our appliances are the perfect match for the platform. Leave the hardware research, testing, and support to us, so you can focus on what's important for your organization. Not only will you have confidence that your Security Onion deployment is running on the best-suited hardware, you will also be supporting future development and maintenance of the Security Onion project!

https://securityonion.com/hardware

Cloud Installations

For new Security Onion 2 installations in the cloud, this new version will soon be available on the AWS, Azure, and GCP marketplaces!

AWS Marketplace and Documentation:

https://securityonion.net/aws/?ref=_ptnr_soc_blog_250625

https://docs.securityonion.net/en/2.4/cloud-amazon.html

Azure Marketplace and documentation:

https://securityonion.net/azure

https://docs.securityonion.net/en/2.4/cloud-azure.html

GCP Marketplace and documentation:

https://securityonion.net/google

https://docs.securityonion.net/en/2.4/cloud-google.html

Screenshot Tour

If you want the quickest and easiest way to try out Security Onion 2.4, just follow the screenshots below to install an Import node. This can be done in a minimal VM with only 4GB RAM! For more information, please see:

https://docs.securityonion.net/en/2.4/first-time-users.html