Company lists · Data refreshed September 2026

Top 25 Managed security service providers based in San Francisco, United States

RevenueBase identified 86 managed security service providers headquartered in San Francisco, United States as of September 2026 and tracks 5,485 professional contacts across them, including 1,350 with verified work emails. New York is the largest hub.

This list covers managed security service providers headquartered in San Francisco, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 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 HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
86Companies
5,485Contacts tracked
1,350Verified emails
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The 25 largest managed security service providers based in San Francisco, United States

Ranked by team size
Top 25 of 86 managed security service providers based in San Francisco, United States, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names managed security service providers: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
BugcrowdPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 2026n/a3,649

“We are a crowdsourced security company that safeguards organizations' assets from sophisticated threat actors before they can strike-by uniting our customers with trusted hackers…”

Source: company website · checked Sep 5, 2026
2
Coalition, INCIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 2026501-1,000724

“Coalition is the world's first Active Insurance provider designed to help prevent digital risk before it strikes.”

Source: company website · checked Sep 5, 2026
3
Nozomi NetworksIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 2026201-500375

“We protect the world’s critical infrastructure from cyber threats.”

Source: company website · checked Sep 5, 2026
4
TAC SecurityStrong evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202651-200208

“TAC Security (NSE: TAC) TAC Security, a leading publicly listed global cybersecurity company specializing in vulnerability management, today serves clients across 100 countries…”

Source: company website · checked Sep 5, 2026
5
CloudmarkIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202651-20053

“Cloudmark was acquired by Proofpoint.”

Source: company website · checked Sep 5, 2026
6
UpfortPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5029

“Upfort is a leading platform for cyber security and insurance that provides holistic protection from evolving cyber threats.”

Source: company website · checked Sep 5, 2026
7
DatawayIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5028

“Dataway, Inc.”

Source: company website · checked Sep 5, 2026
8
SeworksIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5027

“We specialize in Web Application and API penetration Testing, Cyber Threat Intelligence, and Detecting Account Takeovers (ATOs) from attackers.”

Source: company website · checked Sep 5, 2026
9
ActifileIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5025

“Actifile helps organizations automate their Data Discovery, Monitoring and Protection needs, addressing external data threats (like ransomware), insider threats (like shadow IT)…”

Source: company website · checked Sep 5, 2026
10
AtomusStrong evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5024

“A technology driven Managed Security Service Provider purpose built for Aerospace and Defense.”

Source: company website · checked Sep 5, 2026
11
SentantIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5024

“Sentant is a next-generation cybersecurity & IT services firm with a team of experienced technology professionals.”

Source: company website · checked Sep 5, 2026
12
CentarusPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5022

“Centarus is dedicated to providing dependable Managed IT & Cybersecurity support to firms that want to increase efficiency & stay secure.”

Source: company website · checked Sep 5, 2026
13
Code RED PartnersPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 20261-1020

“Code Red specializes in cyber security staffing.”

Source: company website · checked Sep 5, 2026
14
YsecurityIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5014

“We are a team of cybersecurity operators from Silicon Valley.”

Source: company website · checked Sep 5, 2026
15
ZAUNIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5010

“AI is spreading uncontrollably across your organization.”

Source: company website · checked Sep 5, 2026
16
SecuriseaPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-5010

“At Securisea, we are trusted and proven experts in compliance and security.”

Source: company website · checked Sep 5, 2026
17
Metabase QPartial evidence
San Francisco, United StatesHQ checked Sep 5, 202651-2009

“Metabase Q offers an end-to-end platform that enables businesses to manage, measure and mature their cybersecurity.”

Source: company website · checked Sep 5, 2026
18
Humanize, INCIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-506

“Humanize is an innovative and data-conscious company that transforms cybersecurity weaknesses to human readable quantified risks for C-Suite.”

Source: company website · checked Sep 5, 2026
19
Startup DefenseIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-505

“Enterprise Cybersecurity Made Simple”

Source: company website · checked Sep 5, 2026
20
909cyberIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 20261-105

“Fraud doesn’t break in.”

Source: company website · checked Sep 5, 2026
21
Dogpatch Solutions INCIndirect evidence
San Francisco, CA, United StatesHQ checked Sep 5, 20261-104

“Dogpatch Solutions is a leading IT consulting firm that specializes in cybersecurity assessments, migrations, networking and cloud computing solutions.”

Source: company website · checked Sep 5, 2026
22
Usdn INCPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-504

Security Operations Center • Litigation Support • Forensic Lab Email: usdnlab@usdn.net Global Toll Free: 866.930.4312 Non-Emergency: PGP Key: usdnlab@usdn.net -BEGIN PGP PUBLIC…”

Source: company website · checked Sep 5, 2026
23San Francisco, CA, United StatesHQ checked Sep 5, 20261-104

“At XIVX Risk & Threat Intelligence, we help groups minimize risk, understand threats, and achieve compliance the right way: through functional and effective cybersecurity.”

Source: company website · checked Sep 5, 2026
24
TekleapPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 202611-503

“With over two decades of experience in sensitive data management across hundreds of clients and installations, we at TekLeap understand the inherent weaknesses and threats in…”

Source: company website · checked Sep 5, 2026
25
ServadusPartial evidence
San Francisco, CA, United StatesHQ checked Sep 5, 20261-103

“Cybersecurity by Design, we help organizations with their cybersecurity and compliance programs through management and sustainability, consulting, and assessing.”

Source: company website · checked Sep 5, 2026

Showing 25 of 86 managed security service providers based in San Francisco, United States

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Managed security service providers based in San Francisco, United States at a glance

As of Sep 5, 2026
11-50Median size (employees)
New YorkLargest hub · 200 HQs
Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
40
11-50
32
51-200
8
201-500
3
501-1,000
1

Email recency for this list is measured across the whole United States list rather than this city, so it is reported there. Company counts and contact totals on this page are exact for San Francisco, over 86 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among managed security service providers, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

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
Companies headquartered in San Francisco, United States whose own description of what they do matches “managed security service providers”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among managed security service providers, and records with no verified work email. Companies headquartered outside San Francisco are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
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 listed company carries at least one verified work email, 1,350 across the full list. 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 September 5, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Managed security service providers by metro in the United States

Frequently asked

How many managed security service providers are there based in San Francisco, United States?

RevenueBase identified 86 managed security service providers headquartered in San Francisco, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Bugcrowd, headquartered in San Francisco, tops this list with the largest team on record.

Which city has the most managed security service providers?

New York leads with 200 headquartered companies, followed by Houston (120) and Austin (117).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,350 verified decision-maker contacts tracked across these 86 companies.

How current is this list?

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