Top 10 Security Mistakes Developers Make in 2026

SANGKUR — Sun, 17 May 2026 16:44:20 +0000

After analyzing thousands of codebases, here are the most common security issues we find — ranked by frequency.

1. Hardcoded Secrets (73% of repos)

API keys, database passwords, and JWT secrets committed directly to source code.

Quick fix: Use environment variables and .env files (gitignored). Set up git pre-commit hooks with tools like git-secrets.

2. Missing Input Validation (68%)

User input goes directly to database queries, file operations, or shell commands without any validation.

Quick fix: Validate ALL inputs at the boundary. Use schema validation (Zod, Joi, Pydantic) and parameterized queries.

3. Broken Access Control / IDOR (54%)

Users can access other users' data by changing an ID in the URL.

Quick fix: Always check resource ownership: WHERE id = ? AND user_id = ?

4. No Rate Limiting (61%)

Quick fix: Use slowapi (Python), express-rate-limit (Node.js), or your CDN's rate limiting.

5. Sequential IDs Exposed (47%)

Sequential IDs in URLs make it trivial to enumerate resources.

Quick fix: Use UUIDs for public-facing IDs. Keep sequential IDs for internal use only.

6. Missing Security Headers (82%)

No CSP, no X-Frame-Options, no Strict-Transport-Security.

Quick fix: Add security headers via middleware or CDN config. Test at securityheaders.com.

7. SQL Injection (31%)

Still prevalent in PHP and Python codebases that use string formatting for queries.

Quick fix: Use parameterized queries or an ORM. Never concatenate user input into SQL.

# ❌ Vulnerable
cursor.execute(f"SELECT * FROM users WHERE id = {user_id}")

# ✅ Safe
cursor.execute("SELECT * FROM users WHERE id = %s", (user_id,))

8. Weak Cryptography (39%)

MD5 or SHA1 for password hashing, weak encryption algorithms.

Quick fix: bcrypt/argon2 for passwords, AES-256-GCM for encryption.

9. Verbose Error Messages (56%)

Stack traces and internal paths exposed to users in production.

Quick fix: Catch all errors at the boundary, log internally, return generic messages to users.

10. Outdated Dependencies (44%)

Known CVEs in npm packages, pip requirements, or Composer dependencies.

Quick fix: Enable Dependabot/Renovate, run npm audit in CI, update regularly.

How to check your code automatically

I built SANGKUR to detect all 10 of these issues automatically. It uses a 5-engine pipeline:

Pattern matching (540+ rules)
Taint analysis (tracks user input → dangerous sinks)
AST analysis (understands code structure)
Cross-file data flow
AI analysis with CVSS scoring

It's free to try — 30 scans/month, no credit card. Supports 23+ languages.

Try it: sangkur.com

What security issues do you see most often in code reviews? Let me know in the comments 👇

DEV Community: SANGKUR