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YC Security companies

125 Y Combinator companies in Security, with team size, growth, open roles and funding.

Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.

Hiring the mostlast 60 days
67 roles
TRM LabsS19
  1. 2Infisical11
  2. 3Vanta9
See all 18
Fastest growingteam, 6 months
+220%
ParameterW26
  1. 2Casco+75%
  2. 3Infisical+58%
See all 26
Shrinkingteam, 12 months
−32%
QuantstampW18
  1. 2ContraForce−24%
  2. 3Termius−16%
See all 9
Raised the mostlast 12 months
$70M
TRM LabsS19
  1. 2Cinder$41M
  2. 3Tolmo$22M
See all 13
Companies
125
Active
93
Hiring, last 60 days
18
Open roles, 60 days
135
People on these teams
5,298
Showing 50 of 125 companies
CompanyBatchTeam6 mo12 moOpen rolesTotal raisedLast round
Vanta, the proven leader in automated compliance helping startups…
W181,993+6%+34%9$503MSeries D$150M, Jul 2025
TRM is building a safer world for billions of people.
S19481+14%+36%67$220MSeries C$70M, Sep 2026
The Leader in Digital Trust & Safety
S11283+6%−12%4$157MSecondary$50M, Feb 2022
Cybersecurity awareness for fast growing companies
W20260+10%+47%YC$44.2MSeries B$30M, Feb 2025
Cyble - World’s First Intelligence-Driven, AI-Native Security…
W212300%−9%1$44.8MSeries B$6.2M, Nov 2023
Protects organizations from getting breached through their APIs.
W16208+4%+6%1$271MUndisclosed round$140M, Sep 2022
AI company transforming enterprise physical security to prevent…
W17157+1%+8%3$72.1MUndisclosed round$20M, Oct 2023
Enable creators and developers to generate realistic AI personas
S17147−9%+6%2$47.9MSeries B$25M, Mar 2022
The Notabene platform is the trust layer for global money movement.
S20112−2%+8%YC$38.5MCorporate round$11.5M, Jul 2026
Enterprise Deepfake Detection
W2294+15%+25%5$48.6MCorporate round$86K, Sep 2026
Offensive security for the teams that are 100x outnumbered
W2377+28%+64%YC$23.8MSeries A$17.9M, Mar 2026
Opt out software that removes your private info from the internet
W22Acquired64−6%−14%0$2.7MUndisclosed round$2.7M, Sep 2025
Infrastructure to protect companies from AI abuse
W2260+54%+107%4$55MSeries B$41M, May 2026
Block bots & bad behavior
W1656+8%+24%YC$11.6MUndisclosed round$9.2M, Jan 2021
YC's most popular security compliance platform (SOC 2, ISO 27001,…
S2253+26%+77%7$35.5MSeries A$33M, Oct 2025
Security auditing for Web3
W1852−5%−32%0$3.2MSeries A$3.1M, Jun 2022
AI-powered Compliance Platform for PCI 4, CCPA, HIPAA, CIPA, 50+ laws
W2151−4%+38%0$25.8MSeries A$14M, Nov 2025
Detect Gunshots | Inform Law Enforcement | Empower First Responders
W1651+19%+31%0$2.1MSeed$2.1M, Aug 2016
Security infrastructure for developers and agents
W2349+58%+133%11$18.9MSeries A$16M, Jun 2025
Agency replaces traditional security and compliance headcount with AI.
W2247−2%+24%YC$500KNon-equity support$500K, Feb 2025
Manage every device. Govern every AI agent.
S20430%−2%YC$3MSeed$1.5M, Jun 2025
Detect cyber attacks on critical physical infrastructure
W2235+21%+30%0$550KGrant$50K, Jun 2023
Anjuna enabled organizations to trust any infrastructure
W1835+6%+13%0$67.1MSeries B$25M, Aug 2024
Trust Center platform that scales customer security reviews
S20Acquired33−13%−35%0$53.1MSeries B$33M, Apr 2024
Access control management app for Latam´s gated communities
W2232−16%−11%0$1.4MSeed$665K, Feb 2022
Enterprise software for enterprise risk and cyber fraud intelligence
S2229+32%+71%0$19.9MSeries A$15M, Oct 2026
Canix makes it easy to get and stay compliant as a cannabis business.
S1928+4%−3%0$14MSeries A$10M, Jun 2022
Termius is an SSH client with team collaboration features
W1926−4%−16%0$2.7MSeed$2.7M, Jun 2019
Automate security and privacy reviews
S2425+47%+67%2$13.4MSeed$8.4M, Feb 2026
Turnkey security & hassle-free cyber insurance from leading insurers
S1724−8%−8%0$15MSeries A$8M, Oct 2023
Cloud and Container Security Platform
S2122+5%+22%0Seed (before YC)May 2021
Autonomous security testing for web apps, APIs, cloud, and AI systems
X2521+75%+200%YC$17.2MSeries A$13M, Jul 2026
LLM Security and Compliance
W2420+18%+33%YC$3.2MSeed$3.2M, Apr 2024
AI Agents for Fraud Review and Investigations
W2320+18%+54%YC$25.1MSeries A$21.5M, Mar 2026
Security Delivery Platform to orchestrate AI agents for Service…
S2119 −24%0$3.7MSeed$3.3M, Oct 2024
AI pentesting, that works!
W2616+220% 7$500KYC investment$500K, Mar 2026
Tolmo is the AI security platform that secures every layer of cloud…
X2613+44% 5$22MSeed$22M, Jun 2026
Automatically find and fix your software vulnerabilities
S2413+44%+86%0$5.5MSeed$5M, Sep 2025
Use AI tools without fear of data leakage
S2412−25% YC$4.5MSeed$4M, May 2025
Data Discovery, DLP, DSPM for SaaS, Cloud, Gen AI & Endpoints
W2212  1$4MSeed$3.5M, Jul 2022
Easiest way to set up Zero Trust Access for your team
W22120%0%0$500KYC investment$500K, Apr 2022
Open source alternative to Auth0 / AWS Cognito / Firebase Auth
S2010−17%−44%YC$5MSeed$3.5M, Jan 2023
Scan your SaaS apps and instantly identify security issues
S20Acquired10−9% 0$2.1MSeed$2M, Oct 2020
AI agent for Compliance Questionnaires Automation
W2010+11% 1$900KNon-equity support$900K, Nov 2020
Encrypted AI with verifiable privacy
X259+80%+80%0$7.8MSeed$7.1M, Jul 2025
Security operations optimized for agents.
X259+80% YC$500KYC investment$500K, Jun 2025
Autonomous offensive security agents. The best defense is offense
S268  0
Open-source agentic security automation platform
W248+14%+14%1$500KYC investment$500K, Jan 2024
Corgea finds, and fixes insecure code and packages autonomously.
S238+14%+33%YC$2.6MSeed$2.6M, Nov 2024
A live watermark inside AI voice that survives phone calls
F267−42%−12%0$920KPre-seed (before YC)$920K, Sep 2025

How this works

1. The roster

Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.

2. The numbers

Each company is matched to Crustdata by its website. Crustdata adds team size and its change over 6 and 12 months, open roles from job postings, reported funding, and founders' past employers.

3. The lists

Hiring the most counts distinct roles posted in the last 60 days. Growth needs 10+ people today, shrinking 20+ a year ago, so tiny teams do not top the lists. Rebuilt every week.

Built with Crustdata. Get your own API key and build your own.

The numbers on this page come from three Crustdata API calls. Crustdata tags 5,000+ companies with Y Combinator as an investor; swap the filter for any investor, industry or headcount range and track your own list, with founders' work emails one call away.

  • Company search for team size, growth and funding
  • Job search with a count by company, for who is hiring and for what
  • A watch that re-runs the search weekly and sends only what changed
# 1. every company with Y Combinator as an investor
curl https://api.crustdata.com/company/search \
  -H "authorization: Bearer $CRUSTDATA_API_KEY" \
  -H "x-api-version: 2025-11-01" \
  -d '{
    "filters": { "field": "funding.investors",
                 "type": "in", "value": ["Y Combinator"] },
    "fields": ["basic_info.name",
      "headcount.total", "headcount.growth_percent",
      "funding.total_investment_usd"],
    "limit": 100
  }'

# 2. open listings per company, last 60 days (limit 0 = counts only)
curl https://api.crustdata.com/job/search \
  -H "authorization: Bearer $CRUSTDATA_API_KEY" \
  -H "x-api-version: 2025-11-01" \
  -d '{
  "filters": { "op": "and", "conditions": [
    { "field": "company.basic_info.company_id",
      "type": "in", "value": [...] },
    { "field": "metadata.date_added",
      "type": "=>", "value": "2026-08-24" } ]},
  "limit": 0,
  "aggregations": [{ "type": "group_by",
    "field": "company.basic_info.company_id", "agg": "count" }]
}'

# 3. the same company filter as a weekly watch: POST /watch/company/search

Questions about YC Security companies

How many YC Security companies are there?

125 Y Combinator companies are in Security; 93 are active.

Which YC Security companies are hiring?

18 companies posted roles in the last 60 days, led by TRM Labs (67 roles), Infisical (11 roles) and Vanta (9 roles). 38 mark themselves as hiring on YC's directory.

Which YC Security companies are growing fastest?

By team growth over 6 months (10+ people): Parameter (+220%), Casco (+75%) and Infisical (+58%).

Which YC Security companies raised the most?

Largest latest rounds in the last 12 months, after their YC batch: TRM Labs ($70M), Cinder ($41M) and Tolmo ($22M).

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