Audit your SaaS application against 30 essential security checks. Check off items, get a score, and identify what to fix first.
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This checklist covers common security best practices for SaaS applications. It is not exhaustive — consider a professional security audit for production applications handling sensitive data.
A SaaS security checklist is a structured pass over the parts of your application most likely to leak data or let an attacker in: authentication, your database, your API surface, the frontend, your infrastructure, and what you monitor after launch. The 30 checks above are the baseline most indie SaaS apps miss, grouped so you can work through one category at a time and see where the gaps are.
Most breaches start at the login screen. Hash passwords with bcrypt or argon2, rate-limit login attempts, verify email before granting access, and offer TOTP-based two-factor for sensitive accounts. If you use OAuth, validate the state parameter on every callback to block CSRF.
Enable Row Level Security (RLS) on every table and deny by default, so a leaked client key cannot read another tenant's rows. Use parameterized queries everywhere to close off SQL injection, and confirm encryption at rest and automated backups are actually switched on.
Validate every input with a schema (Zod is the common choice in the Next.js world), authenticate every endpoint, rate-limit to blunt abuse, lock CORS to known origins, and keep tokens and PII out of URLs where they end up in server logs and browser history.
Set a Content Security Policy to contain cross-site scripting, never render unsanitized user HTML, and keep secrets out of the client bundle. A single service role key exposed through a NEXT_PUBLIC_ variable is a full database compromise.
Serve everything over HTTPS with HSTS, keep secrets in environment variables rather than the repository, scan dependencies for known vulnerabilities, set your security headers, and make sure stack traces never reach production error responses.
You cannot respond to what you cannot see. Log authentication and admin events, alert on unusual login patterns, monitor uptime, and write the incident response plan before you need it, not during the incident.
Work top to bottom, check off what you already have in place, and treat anything left unchecked as a finding to triage. The grade is a rough signal, not a certification: a B with MFA and RLS in place beats an A that skipped them. For an application handling payments or sensitive personal data, pair this with a professional security audit before launch.
Next.js Security Checklist: 12 Steps [2026]
The Next.js-specific deep dive that pairs with this generic SaaS checklist. CSP, RLS, webhooks, validation, more.
Backend-Only Data Access in Next.js + Supabase
The architectural pattern that makes most checklist items obsolete by removing the attack surface entirely.
OWASP Top 10:2025 for Next.js + Supabase Apps
Every OWASP 2025 category mapped to a Next.js + Supabase failure mode and the architectural defense. Use alongside this checklist for the bigger picture.
Pre-Launch Security Audit: 12 Checks That Matter Most
The audit walkthrough that pairs with this 30-check tool. Run the 12 highest-impact checks in audit order, then triage findings BLOCK / FIX / ACCEPT.
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