Security
Startup security checklist 2026: 40+ must-haves before Series A
Enterprise investors and customers will scrutinize your security posture at Series A. Most startups discover their security gaps during due diligence — which is the worst possible time. Use this checklist before then.
By Aravind Srinivas··12 min read
Authentication & Access Control
- MFA required for all admin accounts and production access
- SSO enforced for internal tools (Google Workspace, GitHub, AWS)
- Principle of least privilege applied to all IAM roles
- Service accounts audited and rotated quarterly
- All API keys stored in secrets manager (AWS Secrets Manager, Vault, or Doppler)
- No secrets in environment variables checked into git
- Session expiry configured for all web applications
- Password complexity requirements enforced
Data Protection
- Encryption at rest for all databases (RDS, S3, etc.)
- Encryption in transit (TLS 1.2+ for all connections)
- PII data identified, classified, and access-controlled
- Database backups encrypted and tested regularly
- Data retention policy documented and enforced
- GDPR/CCPA compliance documented if applicable
- Third-party data sharing agreements reviewed
Application Security
- OWASP Top 10 vulnerabilities addressed (SQL injection, XSS, CSRF, etc.)
- All user inputs validated and sanitized
- HTTPS enforced site-wide with HSTS headers
- Content Security Policy (CSP) headers configured
- Dependencies audited for known vulnerabilities (Dependabot or Snyk)
- Sensitive endpoints rate-limited to prevent brute force
- File upload validation with type checking and size limits
- Error messages don't expose stack traces in production
AI/LLM Security
- Prompt injection protection implemented for all user-facing LLM inputs
- LLM output validation before rendering (no unsanitized HTML)
- User data not sent to LLM APIs without explicit consent
- Data residency requirements met for LLM API providers
- PII redaction before LLM API calls where applicable
- LLM API keys scoped with minimum required permissions
- Rate limits on LLM API calls per user to prevent abuse
- Audit logging for all LLM interactions involving sensitive data
Infrastructure & DevOps
- Production infrastructure not directly accessible from public internet (use VPN/bastion)
- Security groups / firewall rules audited and documented
- Automated vulnerability scanning in CI/CD pipeline
- Production deployments require code review approval
- Audit logs enabled for all production infrastructure changes
- Automated database backups with tested restore procedure
- DDoS protection enabled (Cloudflare or AWS Shield at minimum)
- Infrastructure changes tracked in code (Terraform or CDK)
Incident Response
- Incident response plan documented and shared with team
- Security monitoring and alerting configured (unusual login, privilege escalation, etc.)
- On-call rotation defined for security incidents
- Breach notification process documented (who to notify, timeline)
- Bug bounty policy or responsible disclosure page in place
- Post-incident review process defined
SOC 2 Readiness (if selling enterprise)
- SOC 2 Type II scope defined (Security, Availability, Confidentiality)
- Compliance automation tool in place (Vanta or Drata)
- All controls mapped to SOC 2 trust service criteria
- Employee security training completed and documented
- Background checks process implemented for new hires
- Vendor risk assessments completed for critical third parties
Get a security audit before your Series A
HyperNest Labs provides VAPT (Vulnerability Assessment & Penetration Testing) and security architecture reviews for startups preparing for Series A or enterprise sales. We've helped secure platforms handling healthcare, fintech, and consumer data.