Beginners often try advanced bugs and get stuck. Instead, focus on simple, common vulnerabilities that appear on real websites.
Here are Top 5 Beginner Vulnerabilities you should learn first.
1. IDOR (Insecure Direct Object Reference)

IDOR happens when you can access another user's data by changing an ID in the URL or request.
Example
https://example.com/profile?id=1001Change to:
https://example.com/profile?id=1002If you see another user's data → IDOR found
Where to test
- Profile pages
- Order history
- Invoice download
- API requests
- File downloads
Why beginners should learn this
- Very common vulnerability
- Easy to test
- No coding required
- High impact
SEO keywords: IDOR vulnerability, IDOR bug bounty, IDOR example, access control vulnerability
2. Reflected XSS (Cross-Site Scripting)

Reflected XSS happens when user input is reflected in the page without proper filtering.
Example
Search box:
https://example.com/search?q=testTry:
<script>alert(1)</script>If popup appears → Reflected XSS
Where to test
- Search boxes
- Filters
- Login errors
- URL parameters
- Contact forms
Why beginners should learn this
- Easy to understand
- Found in many websites
- Great first XSS practice
3. Open Redirect

Open Redirect happens when a website redirects users to any external site without validation.
Example
https://example.com/redirect?url=google.comChange to:
https://example.com/redirect?url=evil.comIf it redirects → Open Redirect
Where to test
- Login redirects
- Logout pages
- Continue buttons
- Return URL parameters
Why beginners should learn this
- Very easy to test
- Good for understanding parameters
- Common in real applications
SEO keywords: open redirect vulnerability, open redirect bug bounty, redirect parameter testing
4. Information Disclosure

This happens when sensitive data is exposed accidentally.
Common examples
/robots.txt.gitfolder/backup.zip/admin/test/phpinfo.php
What to look for
- API keys
- Emails
- Internal paths
- Debug messages
- Version info
Why beginners should learn this
- No exploitation required
- Just find exposed data
- Very beginner friendly
SEO keywords: information disclosure vulnerability, sensitive data exposure, bug bounty beginner
5. Broken Authentication

This happens when login or authentication logic is weak.
Example
Try logging in with:
admin:admin
test:test
user:userOr test:
- Password reset
- OTP bypass
- Session reuse
- Remember me token
Why beginners should learn this
- Found in many apps
- High impact
- Good for learning auth logic
SEO keywords: broken authentication bug bounty, login bypass vulnerability, authentication testing
Quick Beginner Testing Checklist
Start testing these first:
✓ Change IDs (IDOR) ✓ Test inputs (XSS) ✓ Modify redirect URLs ✓ Check hidden files ✓ Test login logic
Final Thoughts
You don't need coding to start bug bounty.
Start with:
- IDOR
- XSS
- Open Redirect
- Info Disclosure
- Broken Authentication
These vulnerabilities:
- Are beginner friendly
- Appear in real targets
- Help build hacker mindset
- Improve testing skills fast
Master these first, then move to advanced bugs.