Security Testing with OWASP — Practical Guide for 2026
Security bugs are the most expensive to fix. A single breach can cost millions, end careers, and destroy user trust. Here's the OWASP-aligned security testing playbook we use on every client project.
Security testing isn't optional. It's not something you "get to eventually." Every production system with users is under constant automated attack.
This post covers the OWASP-aligned security testing practices we run on client projects, and how to start if your team has never done formal security testing.
The OWASP Top 10 in 2026
- Broken access control
- Cryptographic failures
- Injection
- Insecure design
- Security misconfiguration
- Vulnerable components
- Authentication failures
- Data integrity failures
- Logging failures
- SSRF
Every production system should test against all 10.
Testing categories
Static analysis (SAST) — Scan source for vulnerabilities. Tools: Snyk, SonarQube, Semgrep.
Dynamic analysis (DAST) — Test running apps. Tools: OWASP ZAP, Burp Suite.
Dependency scanning — Check third-party libs for CVEs. Tools: npm audit, Snyk, Dependabot.
Manual penetration testing — Human experts attempt real attacks.
Authentication and session testing
Common vulnerabilities:
- Missing rate limiting on login endpoints
- Weak password reset flows
- Session tokens that don't expire
- Session fixation
- Missing CSRF protection
- Auth tokens stored in localStorage
- No account lockout after failed logins
API security testing
- Missing auth on endpoints
- IDOR (Insecure Direct Object Reference)
- Mass assignment
- Rate limiting absence
- Excessive data exposure
- Misconfigured CORS
How to start
- Run dependency scans today (fastest win)
- Run OWASP ZAP against staging (free, automated)
- Add SAST to CI (Snyk or Semgrep)
- Do manual auth testing
- Test API endpoints for auth and IDOR
- Schedule annual penetration tests
What "done" looks like
- No critical/high findings open
- All dependencies updated or exceptions documented
- Auth flows manually tested
- API endpoints validated
- Logging and alerting in place
- Incident response plan documented
Common mistakes
- Treating security as a one-time project
- Only running automated scanners
- Skipping auth testing
- Not testing the API layer
- Delaying fixes
Key takeaways
- Every production system is under attack — test first
- Cover all 10 OWASP categories
- Layer SAST, DAST, dependency scans, and manual testing
- Auth and API testing catch the most common real-world bugs
- Security testing is continuous, not one-time
Further reading
About the author
Senior QA Engineer →Senior QA Engineer · Quality Assurance Labs
