Nuclei

Nuclei is a fast, template-driven vulnerability scanner that uses a community-powered library of YAML templates to detect CVEs, misconfigurations, exposed panels, and default credentials at scale.

Vulnerability Scanning open-source vulnerability-scanner attack-surface-management penetration-testing

Overview

Nuclei is a free and open-source vulnerability scanner developed by ProjectDiscovery that uses a template-based engine to perform fast, targeted security checks across hosts, URLs, and network services. Templates are written in simple YAML and describe how to send requests, match responses, and extract results, allowing the community to rapidly publish detection logic for new CVEs. The official nuclei-templates repository contains thousands of community-maintained templates covering CVEs, misconfigurations, exposed admin panels, default credentials, takeover risks, and cloud metadata exposure. Nuclei supports HTTP, DNS, TCP, SSL, WebSocket, WHOIS, and headless browser protocols, and it scales across large asset inventories with high concurrency. As of 2026, recent releases added AI-assisted template generation, improved fuzzing and DAST capabilities, and deeper integration with the ProjectDiscovery cloud platform.

Primary Use Cases

✔ Rapid CVE detection across large asset inventories using community-maintained templates that are updated within hours of new vulnerability disclosures.

✔ Continuous attack surface management by integrating with subfinder, httpx, and other ProjectDiscovery tools to scan newly discovered assets for exposures.

✔ Custom security checks during penetration tests by authoring YAML templates for organization-specific misconfigurations, business logic flaws, and proprietary service fingerprints.

Frequently Asked Questions

Yes. Nuclei is released under the MIT license and maintained by ProjectDiscovery. The core engine and the community nuclei-templates repository are freely available, though ProjectDiscovery also offers a paid cloud platform with additional features.

As of September 2026, the current stable release is Nuclei v3.x, which introduced a reworked template engine, native fuzzing and DAST support, and AI-assisted template generation. The community nuclei-templates repository now contains over 10,000 templates.

Traditional scanners like Nessus and OpenVAS use proprietary or complex plugin formats and are typically run on scheduled scans of internal networks. Nuclei uses simple YAML templates that anyone can write, enabling the community to publish detection logic for new CVEs within hours. It is also designed for high-speed, large-scale scanning of internet-facing assets and integrates tightly with other ProjectDiscovery tools for pipeline-based workflows.

Yes. Nuclei is commonly integrated into CI/CD pipelines and scheduled scans to continuously check production and staging assets for newly disclosed vulnerabilities. Combined with subfinder and httpx for asset discovery, it forms a scalable continuous attack surface monitoring pipeline.

Yes. Nuclei templates are written in simple YAML and support matchers, extractors, DSL expressions, and multi-step workflows. The official documentation provides a template guide, and ProjectDiscovery offers a template editor and cloud-based template validation. Custom templates can be kept private or contributed back to the community repository.

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Category Info

Vulnerability Scanning covers tools that identify known CVEs, misconfigurations, exposed services, and weaknesses across hosts, networks, and web applications to support offensive security testing and attack surface management.

Added On

September 16, 2026

Last Updated

September 16, 2026