Open by design, trusted by enterprises: how we keep Nuclei templates reliable at scale

Intro

If you haven’t met us yet: ProjectDiscovery is the company behind Nuclei and ProjectDiscovery Cloud; a modern approach to vulnerability detection built on evidence of exploitability, not guesswork. Nuclei is our open-source engine that runs simple, auditable templates mirroring what a security researcher would do to confirm whether something is actually exploitable, but safely and at scale.

When you work with ProjectDiscovery, you’re tapping into a global research bench of 10,000+ contributors who surface trending vulnerabilities and exploits, and propose checks faster than any single vendor team could. That scale is unique in the land of Vulnerability Management, and it’s why many practitioner teams tell their leaders to “check out Nuclei.”

If you’re running an enterprise security team, that promise raises a fair question: Can community-driven content be trusted in a business-critical program? We think that’s the right question to ask, and we’re proud to dive into the details of our process to reveal the strength and rigor that runs deep in our DNA.

Every scan in Nuclei is powered by a YAML-based template; a small, auditable playbook that validates exploitability on a specific endpoint. Instead of version strings or banner checks, Nuclei safely reproduces attacker-like behavior automatically, across every reachable asset, at runtime and at scale.

While traditional scanners like Tenable or Qualys focus on theoretical exposure, Nuclei focuses on real exploitability. That difference (proof over guesswork) is why practitioners reach for Nuclei when the question is, “Are we actually vulnerable?”

This blog gives a peek under the hood at what makes our community-driven power and speed enterprise-ready. We’ll look at how templates are proposed, reproduced in our labs, hardened by checklists, double-reviewed, and continuously improved in the open. By the end, you’ll see what Nuclei is, how we protect template integrity, and why a global community + a rigorous process produces a cleaner and faster signal for security teams.

A Closer Look at Nuclei Templates

The Nuclei template ecosystem grows through two primary sources:

1. Community contributions: Our global community of 10k+ researchers, bug bounty hunters, and engineers contributes new detections and improvements, often arriving within hours of a new CVE or exploit publication, giving our users unmatched coverage speed.

Example: When a critical remote code execution flaw in a major CMS became public, a researcher submitted a working Nuclei template the same afternoon. Our internal team validated and merged it that same day, giving customers immediate visibility into whether they were exposed.

2. Internal templates team: ProjectDiscovery also maintains a dedicated templates team that tracks multiple data feeds such as CISA KEV, VulnCheck KEV, and vendor advisories. This team writes new templates, validates community submissions, and fills coverage gaps identified through internal telemetry.

Regardless of who generates it, every template must meet the same quality bar before it is accepted. We focus on accuracy, safety, and reproducibility. Each template must:

• Demonstrate real exploitability rather than just version or banner checks.
• Use non-destructive, read-only requests to ensure safe scanning.
• Include clear metadata such as severity, references, and description.
• Reproduce consistently in a controlled vulnerable environment.
• Pass a two-person review before merge.

Example: When CVE-2024-23897 (Jenkins arbitrary file read) was disclosed, the community submitted a template within hours. Our team reproduced it in a lab, confirmed the detection was reliable, ensured the payload was safe, and merged it with full metadata and tags for immediate enterprise scanning.

Template review process, step by step:

1. Submission: A contributor opens a pull request. The PD template team checks the logic, ensures it is safe to run, and verifies metadata completeness.
2. Reproduction: The template team recreates the vulnerable condition in a controlled lab using Docker images, trial licenses, or synthetic environments. The goal is to confirm that the template only triggers when the target is truly vulnerable.
3. Review and refinement: We check that matchers are strict and that detection relies on unique responses, not loose strings like “admin” or “login.”
4. Independent validation: A second reviewer from the templates team then reproduces the detection independently. Only after this validation do we merge the template.
5. Continuous maintenance: After we merge, we monitor reports of false positives or false negatives through GitHub Issues. Updates are released quickly when needed.

All Nuclei templates are stored in our public GitHub repository. Anyone can read, audit, or contribute to them. It’s one of the most active vulnerability detection libraries in the world, with thousands of templates and hundreds of pull requests each month. Many templates appear within hours of new proof-of-concept disclosures.

How the Templates Team Complements the Community

Our internal templates team works alongside the community to ensure coverage is complete and aligned with real-world risk.

1. Filling gaps using real-world data

We continuously compare template coverage against sources, and exploit feeds. When we spot missing detections, we either write them internally or launch bounty opportunities for contributors to fill those gaps quickly.

2. Prioritizing by enterprise impact

We analyze technology adoption across enterprise customers to decide which detections to build first. Products with the widest deployment footprint get priority because that’s where coverage delivers the most protection.

Example: When a vulnerability appeared in a popular enterprise VPN product, our telemetry showed significant customer exposure. The templates team prioritized it immediately, reproduced it in a lab, and released a verified detection within 24 hours.

3. Strengthening community work

When community submissions arrive quickly for new CVEs, our team hardens them.

When you work with ProjectDiscovery, you get the advantage of a huge group of security professionals moving quickly to produce Nuclei templates, while our internal team ensures that every detection meets the bar for enterprise safety, accuracy and completeness.

Nuclei Templates for the Enterprise

Enterprises love ProjectDiscovery. Not only do they benefit from access to expertise from a vast community of security professionals and rapid template generation and delivery for emerging threats, they can also trust that every detection is:

• Reproduced in a lab before release
• Verified by two reviewers
• Safe to run in production environments
• Continuously maintained through community and internal monitoring

This model combines the agility and volume of open source with the control of enterprise QA.

Example: During the Log4Shell incident, an initial community template surfaced within hours. Our team rewrote it to remove destructive payloads, validated it across multiple server configurations, and merged a hardened version the same day. Customers scanning with ProjectDiscovery Cloud received accurate, safe detections without downtime.

The Bottom Line

When transparency meets discipline, open source becomes an advantage for the enterprise, rather than a risk. With Nuclei, you’re not just scanning; you’re running the same evidence-first checks a security researcher would, automatically and safely, across your entire attack surface. The community gives you unparalleled breadth and speed; and our template review pipeline turns that scale into trustworthy, enterprise-ready signal.

Traditional vulnerability management tools inventory what might be exposed, but Nuclei proves what’s actually exploitable, and it does so with thousands of experts behind you. It’s a safe, scalable detection engine, at a pace that legacy scanners simply can’t match.

That’s the quiet superpower of ProjectDiscovery: community-powered coverage, rigorously validated, giving you cleaner signal and faster decisions when it matters most.

Want to learn more about ProjectDiscovery, our community, or Nuclei templates?

Interested in Contributing?

If you want to contribute, everything you need is public!

Start with our CONTRIBUTING guide and Template Review Guide.

We also run a Template Bounty Program that rewards verified, high-impact templates.