Nuclei Cheatsheet: Bug Hunting Made Easy

If you’re doing reconnaissance and not using Nuclei to its full potential, you’re leaving a huge part of the attack surface untouched.
Nuclei isn’t just a scanner anymore…
It’s evolving into a powerful vulnerability research framework used by top bug hunters.
In this guide, you’ll get a practical, real-world Nuclei cheatsheet to level up your bug bounty workflow.

What Is Nuclei and Why It Matters 🎯​

Nuclei is a fast, template-based vulnerability scanner built for modern security testing.
Instead of guessing vulnerabilities, it uses YAML-based templates to detect:

• CVEs
• Misconfigurations
• Exposed services
• Security weaknesses

👉 The real power comes from:

• Automation
• Custom templates
• Massive community template library

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Basic Nuclei Scanning Commands 🔎​

Here are the commands every bug hunter should memorize:

Scan a Single Target​

nuclei -u https://example.com

Scan Multiple Targets​

nuclei -list targets.txt

Run Templates from a Specific Directory​

nuclei -t cves/

Filter by Tags​

nuclei -tags cve,xss

Filter by Severity​

nuclei -severity critical,high

Update Templates (Very Important ⚠️)​

nuclei -update-templates

Run Headless (Browser-Based Checks)​

nuclei -headless

Run Fuzzing Templates​

nuclei -fuzz

👉 These commands alone can cover a massive attack surface quickly.

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Using AI in Nuclei (-ai Flag) 🤖​

One of the most underrated features in modern Nuclei.
It allows you to generate detection logic dynamically.

Generate Templates on the Fly​

nuclei -ai "Find admin_api_key in response"

Detect Debug Information Leaks​

nuclei -ai "Detect exposed stack traces"

Discover Admin Login Endpoints​

nuclei -ai "Find admin login endpoints"

Hunt for Secrets​

nuclei -ai "Detect secrets in response"

Configure AI Authentication​

nuclei -auth

💡 This is extremely useful for:

• Hypothesis testing
• Fast recon
• Finding non-obvious vulnerabilities

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Template Research & Customization 📂​

Understanding templates is what separates beginners from pros.

List Installed Templates​

nuclei -tl

Validate Templates​

nuclei -validate

Display Template Details​

nuclei -template-display

Search Templates by Keyword​

nuclei -tl | grep wordpress

Why Custom Templates Matter​

Public templates are great… but custom templates find hidden bugs.
You can write YAML templates for:

• Exposed admin panels
• Misconfigurations
• Authentication bypass
• IDOR vulnerabilities
• API key leaks
• WAF bypass techniques

👉 This is where real bug bounty wins happen.

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Powerful Recon Workflow (Pro Setup) ⚔️​

Combine Nuclei with other tools for maximum efficiency:

Recommended Pipeline​

subfinder -d target.com | httpx | nuclei -tags cve,exposure

Workflow Breakdown​

• Subfinder → Finds subdomains
• Httpx → Filters live hosts
• Nuclei → Scans for vulnerabilities

👉 This combo gives you deep coverage + speed.

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Targeted Bug Hunting with Tags 🎯​

Use tags to focus your testing:

CVEs​

nuclei -tags cve

Exposures​

nuclei -tags exposure

Misconfigurations​

nuclei -tags misconfig

XSS Vulnerabilities​

nuclei -tags xss

Subdomain Takeovers​

nuclei -tags takeover

👉 Tag-based scanning helps reduce noise and improve accuracy.

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Pro Tips for Serious Bug Hunters 🧠​

✔ Always update templates before scanning
✔ Prioritize critical & high severity findings
✔ Never trust results blindly - verify manually
✔ Adjust rate limits to avoid getting blocked
✔ Use AI + manual testing together
✔ Build your own templates regularly​

👉 Remember:
Automation finds bugs.
Understanding finds critical bugs.

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Advanced Example: Custom Nuclei Template 💻​

Here’s a simple example of a custom template:

id: exposed-api-key

info:
  name: Exposed API Key Detection
  author: you
  severity: high

requests:
  - method: GET
    path:
      - "{{BaseURL}}"

    matchers:
      - type: regex
        regex:
          - "api_key=[A-Za-z0-9]{32}"

👉 This template scans for exposed API keys in responses.

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Final Takeaway 🚀​

Nuclei is no longer “just a scanner.”
It’s becoming a core research tool for bug hunters.
If you’re serious about bug bounty or penetration testing:

👉 Learn templates
👉 Use automation wisely
👉 Think like an attacker​

That’s where the real results are.