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.
| Company | Batch | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
Vanta, the proven leader in automated compliance helping startups… | W18 | 1,993 | +6% | +34% | 9 | $503M | Series D$150M, Jul 2025 |
TRM is building a safer world for billions of people. | S19 | 481 | +14% | +36% | 67 | $220M | Series C$70M, Sep 2026 |
The Leader in Digital Trust & Safety | S11 | 283 | +6% | −12% | 4 | $157M | Secondary$50M, Feb 2022 |
Cybersecurity awareness for fast growing companies | W20 | 260 | +10% | +47% | YC | $44.2M | Series B$30M, Feb 2025 |
Cyble - World’s First Intelligence-Driven, AI-Native Security… | W21 | 230 | 0% | −9% | 1 | $44.8M | Series B$6.2M, Nov 2023 |
Protects organizations from getting breached through their APIs. | W16 | 208 | +4% | +6% | 1 | $271M | Undisclosed round$140M, Sep 2022 |
AI company transforming enterprise physical security to prevent… | W17 | 157 | +1% | +8% | 3 | $72.1M | Undisclosed round$20M, Oct 2023 |
Enable creators and developers to generate realistic AI personas | S17 | 147 | −9% | +6% | 2 | $47.9M | Series B$25M, Mar 2022 |
The Notabene platform is the trust layer for global money movement. | S20 | 112 | −2% | +8% | YC | $38.5M | Corporate round$11.5M, Jul 2026 |
Enterprise Deepfake Detection | W22 | 94 | +15% | +25% | 5 | $48.6M | Corporate round$86K, Sep 2026 |
Offensive security for the teams that are 100x outnumbered | W23 | 77 | +28% | +64% | YC | $23.8M | Series A$17.9M, Mar 2026 |
Opt out software that removes your private info from the internet | W22Acquired | 64 | −6% | −14% | 0 | $2.7M | Undisclosed round$2.7M, Sep 2025 |
Infrastructure to protect companies from AI abuse | W22 | 60 | +54% | +107% | 4 | $55M | Series B$41M, May 2026 |
Block bots & bad behavior | W16 | 56 | +8% | +24% | YC | $11.6M | Undisclosed round$9.2M, Jan 2021 |
YC's most popular security compliance platform (SOC 2, ISO 27001,… | S22 | 53 | +26% | +77% | 7 | $35.5M | Series A$33M, Oct 2025 |
Security auditing for Web3 | W18 | 52 | −5% | −32% | 0 | $3.2M | Series A$3.1M, Jun 2022 |
AI-powered Compliance Platform for PCI 4, CCPA, HIPAA, CIPA, 50+ laws | W21 | 51 | −4% | +38% | 0 | $25.8M | Series A$14M, Nov 2025 |
Detect Gunshots | Inform Law Enforcement | Empower First Responders | W16 | 51 | +19% | +31% | 0 | $2.1M | Seed$2.1M, Aug 2016 |
Security infrastructure for developers and agents | W23 | 49 | +58% | +133% | 11 | $18.9M | Series A$16M, Jun 2025 |
Agency replaces traditional security and compliance headcount with AI. | W22 | 47 | −2% | +24% | YC | $500K | Non-equity support$500K, Feb 2025 |
Manage every device. Govern every AI agent. | S20 | 43 | 0% | −2% | YC | $3M | Seed$1.5M, Jun 2025 |
Detect cyber attacks on critical physical infrastructure | W22 | 35 | +21% | +30% | 0 | $550K | Grant$50K, Jun 2023 |
Anjuna enabled organizations to trust any infrastructure | W18 | 35 | +6% | +13% | 0 | $67.1M | Series B$25M, Aug 2024 |
Trust Center platform that scales customer security reviews | S20Acquired | 33 | −13% | −35% | 0 | $53.1M | Series B$33M, Apr 2024 |
Access control management app for Latam´s gated communities | W22 | 32 | −16% | −11% | 0 | $1.4M | Seed$665K, Feb 2022 |
Enterprise software for enterprise risk and cyber fraud intelligence | S22 | 29 | +32% | +71% | 0 | $19.9M | Series A$15M, Oct 2026 |
Canix makes it easy to get and stay compliant as a cannabis business. | S19 | 28 | +4% | −3% | 0 | $14M | Series A$10M, Jun 2022 |
Termius is an SSH client with team collaboration features | W19 | 26 | −4% | −16% | 0 | $2.7M | Seed$2.7M, Jun 2019 |
Automate security and privacy reviews | S24 | 25 | +47% | +67% | 2 | $13.4M | Seed$8.4M, Feb 2026 |
Turnkey security & hassle-free cyber insurance from leading insurers | S17 | 24 | −8% | −8% | 0 | $15M | Series A$8M, Oct 2023 |
Cloud and Container Security Platform | S21 | 22 | +5% | +22% | 0 | Seed (before YC)May 2021 | |
Autonomous security testing for web apps, APIs, cloud, and AI systems | X25 | 21 | +75% | +200% | YC | $17.2M | Series A$13M, Jul 2026 |
LLM Security and Compliance | W24 | 20 | +18% | +33% | YC | $3.2M | Seed$3.2M, Apr 2024 |
AI Agents for Fraud Review and Investigations | W23 | 20 | +18% | +54% | YC | $25.1M | Series A$21.5M, Mar 2026 |
Security Delivery Platform to orchestrate AI agents for Service… | S21 | 19 | −24% | 0 | $3.7M | Seed$3.3M, Oct 2024 | |
AI pentesting, that works! | W26 | 16 | +220% | 7 | $500K | YC investment$500K, Mar 2026 | |
Tolmo is the AI security platform that secures every layer of cloud… | X26 | 13 | +44% | 5 | $22M | Seed$22M, Jun 2026 | |
Automatically find and fix your software vulnerabilities | S24 | 13 | +44% | +86% | 0 | $5.5M | Seed$5M, Sep 2025 |
Use AI tools without fear of data leakage | S24 | 12 | −25% | YC | $4.5M | Seed$4M, May 2025 | |
Data Discovery, DLP, DSPM for SaaS, Cloud, Gen AI & Endpoints | W22 | 12 | 1 | $4M | Seed$3.5M, Jul 2022 | ||
Easiest way to set up Zero Trust Access for your team | W22 | 12 | 0% | 0% | 0 | $500K | YC investment$500K, Apr 2022 |
Open source alternative to Auth0 / AWS Cognito / Firebase Auth | S20 | 10 | −17% | −44% | YC | $5M | Seed$3.5M, Jan 2023 |
Scan your SaaS apps and instantly identify security issues | S20Acquired | 10 | −9% | 0 | $2.1M | Seed$2M, Oct 2020 | |
AI agent for Compliance Questionnaires Automation | W20 | 10 | +11% | 1 | $900K | Non-equity support$900K, Nov 2020 | |
Encrypted AI with verifiable privacy | X25 | 9 | +80% | +80% | 0 | $7.8M | Seed$7.1M, Jul 2025 |
Security operations optimized for agents. | X25 | 9 | +80% | YC | $500K | YC investment$500K, Jun 2025 | |
Autonomous offensive security agents. The best defense is offense | S26 | 8 | 0 | ||||
Open-source agentic security automation platform | W24 | 8 | +14% | +14% | 1 | $500K | YC investment$500K, Jan 2024 |
Corgea finds, and fixes insecure code and packages autonomously. | S23 | 8 | +14% | +33% | YC | $2.6M | Seed$2.6M, Nov 2024 |
A live watermark inside AI voice that survives phone calls | F26 | 7 | −42% | −12% | 0 | $920K | Pre-seed (before YC)$920K, Sep 2025 |
Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.
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.
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.
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.
# 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
125 Y Combinator companies are in Security; 93 are active.
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.
By team growth over 6 months (10+ people): Parameter (+220%), Casco (+75%) and Infisical (+58%).
Largest latest rounds in the last 12 months, after their YC batch: TRM Labs ($70M), Cinder ($41M) and Tolmo ($22M).