VulnAPI

VulnAPI is an open-source tool for scanning APIs for vulnerabilities, with options for CLI requests, OpenAPI contracts, and GraphQL endpoints. It suits security-minded teams that can run a self-hosted scanner and want security checks in their CI/CD pipelines. Its broad scan coverage and remediation guidance make it a strong free option, though teams should weigh self-hosting and default telemetry collection.

Overview

VulnAPI supports API discovery, authentication and authorization checks, input validation, and business-logic testing. It aims to detect all ten OWASP API Security Top 10 categories out of the box, giving teams a broad starting point for API security assessments. Custom scans let teams adapt assessments to their requirements and environments, though the product’s value depends on teams being able to configure and operate the scanner themselves.

Key features

Flexible scan inputs and useful findings

Teams can scan through a curl-like CLI, an OpenAPI contract, or a GraphQL endpoint. That range accommodates both request-driven checks and schema-based workflows. Reports identify the risk level, vulnerability, description, and affected operation; findings also include the triggering request and concrete remediation steps in plain English. This makes results more actionable than a list of vulnerability names alone.

Pipeline support and proxy configuration

GitHub Actions, GitLab CI, and Jenkins integrations make VulnAPI a practical fit for teams that want API checks in existing delivery pipelines. Proxy settings work through HTTP_PROXY or HTTPS_PROXY environment variables or a --proxy argument, offering flexibility for routed network environments.

Telemetry and community support

The scanner collects anonymous data about scan counts and detected vulnerability counts and severity by default. Users can opt out with a command-line flag, but teams with stricter telemetry policies should account for that setting before deployment. The repository welcomes requests for additional vulnerability checks and best practices through issues and pull requests, a useful route for community contribution rather than a dedicated support promise.

Pricing

VulnAPI is free and open source under the MIT License. The Open source (MIT License) plan costs nothing and permits use, modification, and distribution for educational and testing purposes. No paid tier or additional plan limits are part of the offering described here; the trade-off is that teams handle self-hosting and operation themselves.

Platforms

VulnAPI is self-hosted and supports Linux, macOS, and Windows. Pre-built binaries and installation instructions are provided for those operating systems, and Docker is also available. This gives teams deployment flexibility, but it is not a hosted service.

Who it's for

VulnAPI is best for security-minded teams that want a free, customizable API scanner and can incorporate self-hosted tooling into their workflows. Its multiple scan methods, OWASP coverage, and pipeline integrations suit teams checking APIs across development and delivery. It is less fitting for organizations seeking a managed scanning service or unwilling to collect telemetry without first opting out.

Pros and cons

• Pros: Scans curl-like requests, OpenAPI contracts, and GraphQL endpoints, giving teams several ways to assess APIs.
• Pros: Reports pair vulnerability details with the triggering request and concrete remediation steps, helping teams move from detection to investigation.
• Pros: GitHub Actions, GitLab CI, and Jenkins support makes pipeline integration a clear use case.
• Pros: Free MIT-licensed software can be modified and distributed for educational and testing purposes.
• Cons: Self-hosting means teams must take responsibility for deployment and operation rather than relying on a hosted scanner.
• Cons: Anonymous scan and vulnerability telemetry is collected by default, so teams must use the opt-out flag if that conflicts with their policies.

Alternatives

For a broader comparison, see API Security Testing Software.

• 42Crunch API Security Platform is worth considering for teams seeking a paid platform with a free plan and trial, plus an AI coding plugin, OpenAPI audit, vulnerability scans, and automatic fixes in its free offering.
• OWASP Amass is another free, open-source option for teams looking for an Apache License 2.0 framework.
• APISec Platform may suit teams that prefer a freemium offering with a forever-free plan, public API testing, basic test simulations, and community support.
• Automatic API Attack Tool is an alternative for teams working with Java 8 or higher, Gradle, and Swagger 2.0 API specifications.
• WuppieFuzz is a free, open-source REST API fuzzer for teams focused on that approach.
• AquilaX API Security Scanner is an option for teams seeking a freemium scanner whose free plan includes secrets scanning, PII detection, compliance auditing, unlimited scans, and CI/CD and IDE integrations.
• Pynt may fit teams that want a free Starter plan with limited API security testing for up to 10 API endpoints, or a Business plan with custom pricing.
• Schemathesis is a free, open-source API testing tool that generates tests from OpenAPI and GraphQL schemas.

Verdict

Choose VulnAPI if your team wants a free, self-hosted API security scanner with several scan inputs, broad OWASP coverage, and findings that include practical remediation guidance. Its clearest reason to look elsewhere is the operational responsibility of self-hosting, compounded for some teams by default telemetry that requires an explicit opt-out.