Company lists · Data refreshed November 2026

Top 17 Open source security software companies based in the United States

RevenueBase identified 38 company matches for open source security software companies associated with the United States as of November 2026 and tracks 1,082 professional contacts across them, including 468 with verified work emails. San Francisco is the largest hub.

This list covers company matches for open source security software companies associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list RevenueBase SmartSearch · Exact Recorded Nov 5, 2026 How this list was built
38Companies
1,082Contacts tracked
468Verified emails
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The 17 largest open source security software companies based in the United States

Ranked by team size
Top 17 of 38 company matches for open source security software companies based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 5, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchWilmington, DE, United StatesHQ recorded Nov 5, 2026n/a417 contacts →

Exact match

“The Open Worldwide Application Security Project (OWASP) is a worldwide free and open community focused on improving the security of software.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
2Exact matchTempe, AZ, United StatesHQ recorded Nov 5, 2026201-500357 contacts →

Exact match

“Bishop Fox is recognized as the leading authority in offensive security, providing solutions ranging from continuous penetration testing, red teaming, and attack surface…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3Exact matchAustin, TX, United StatesHQ recorded Nov 5, 202651-20081 contacts →

Exact match

“Secure networks start here.™ Netgate is focused on delivering secure high-performance network connectivity for everyone.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 202611-5047 contacts →

Exact match

“Software ships daily.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5Exact matchBoston, MA, United StatesHQ recorded Nov 5, 202611-5034 contacts →

Exact match

“Root eliminates the CVE grind by delivering open source that is clean of vulnerabilities, secured by default, and ready to use without engineering effort.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6Exact matchEvans, GA, United StatesHQ recorded Nov 5, 202611-5024 contacts →

Exact match

“Doug Burks started the Security Onion project in 2008 to provide a free and open source platform for intrusion detection, network security monitoring, and log management to help…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7Exact matchAtlanta, GA, United StatesHQ recorded Nov 5, 202611-5014 contacts →

Exact match

“RapidFire Tools was acquired in 2018 by Kaseya.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
8Exact matchAnnapolis, MD, United StatesHQ recorded Nov 5, 202611-5011 contacts →

Exact match

“In 2004, we founded KoreLogic to build an IT security company that was respected for the quality of its work and the caliber of our staff.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
9Exact matchChantilly, VA, United StatesHQ recorded Nov 5, 202611-5010 contacts →

Exact match

“Atomicorp eliminates the high cost, complexity and burden of cybersecurity and compliance by harnessing and extending the power of Open Source Security (OSSEC), ModSecurity WAF…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchDenver, CO, United StatesHQ recorded Nov 5, 20261-109 contacts →

Exact match

“At CyberSecurity NonProfit (CSNP), we believe security shouldn't be a privilege reserved for those who can afford it.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11Exact matchDallas, United StatesHQ recorded Nov 5, 202611-509 contacts →

Exact match

“Threatrix is revolutionizing software supply chain security and license compliance with our advanced IDE plugin.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
12Exact matchWesterville, OH, United StatesHQ recorded Nov 5, 20261-105 contacts →

Exact match

“In February of 2015, the Ponemon institute published a survey showing that 43% of American businesses had experienced a security breach in 2014.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13Exact matchHauppague, GA, United StatesHQ recorded Nov 5, 20261-104 contacts →

Exact match

“Its mission: assuring companies have the tools they need to assess and respond to vulnerabilities with speed, precision and confidence.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14Exact matchAlpharetta, GA, United StatesHQ recorded Nov 5, 202651-2003 contacts →

Exact match

“iTivity is the fastest, easiest way to secure vendor systems.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15Exact matchSan Francisco, CA, United StatesHQ recorded Nov 5, 20261-103 contacts →

Exact match

“The top 10 attack techniques haven't changed in a decade.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
16Exact matchTroy, NY, United StatesHQ recorded Nov 5, 20261-102 contacts →

Exact match

“RET2 is a computer security research firm founded in 2017.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17Exact matchSeattle, WA, United StatesHQ recorded Nov 5, 20261-101 contacts →

Exact match

“DevSecFlow is at the forefront of enterprise-grade cybersecurity solutions, specializing in secure product and software development.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

Showing 17 of 38 open source security software companies based in the United States

See the full list, filter by size, metro and specialty, and access 468 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Open source security software companies based in the United States at a glance

As of Nov 5, 2026
43.3%Verified-email coverage
28.5Average contacts per company
1-10Median size (employees)
10.5%Largest-city concentration · San Francisco
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
22
11-50
10
51-200
4
201-500
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 38 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “open source security software companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every displayed company carries at least one verified work email. RevenueBase tracks 468 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on November 5, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “open source security software companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many open source security software companies are there based in the United States?

RevenueBase identified 38 company matches for open source security software companies associated with the United States as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Owasp Foundation tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most open source security software companies?

San Francisco leads with 4 company records, followed by Atlanta (2) and Austin (2).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 468 professional contacts with verified work emails tracked across these 38 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 5, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.