Top 7 Open Source Vulnerability Scanning Tools in 2025

Open-source vulnerability scanning tools offer potent features without a price tag, making them accessible to a wide range of users, from individual developers to large enterprises. Follow the links below to see our rationale for each selected tool:

AIMultiple researched and selected the top 7 open-source vulnerability scanning tools based on our research, the tools’ effectiveness, popularity, community endorsement and reliability. 

Open source vulnerability scanning tools compared

*OS where solution can be deployed Enterprises and mid-market companies may also want to consider the complete set of vulnerability scanning tools which include proprietary software.

Sorting: According to the number of stars on GitHub.

Selection Criteria

• Open source projects: 1000+ stars on GitHub
• Proprietary software: Must be a free-to-use package provided by a vulnerability scanning or DAST software provider

Read more: Open source network security software.

Top Software Analyzed

1. OWASP ZAP (Zed Attack Proxy)

OWASP ZAP is an open-source vulnerability scanner widely used to identify vulnerabilities in web applications. It offers automated scanners for quick assessments and a variety of manual testing tools for in-depth analysis. Key features include an intercepting proxy that allows users to view and modify HTTP/S traffic, spiders to discover the application’s structure, and various utilities for fuzzing and scanning WebSocket connections.

Its extensibility through add-ons and graphical user interface (GUI) makes it accessible to beginners, while its comprehensive feature set caters to advanced users. Despite its strengths, ZAP has a steeper learning curve for its more advanced features. 

2. Nmap (Network Mapper)

Nmap is a versatile open-source tool that is suitible for network discovery and security auditing. It offers a wide range of scanning options, including port scanning, OS detection, service version detection, and more. The Nmap Scripting Engine (NSE) further extends its capabilities, allowing for complex and customizable scanning tasks using scripts.

Nmap is supported on multiple operating systems, including Windows, Linux, and macOS, and is backed by extensive documentation and a strong user community. While it is primarily command-line based, which may pose a challenge to those unfamiliar with command-line interfaces, GUI front-ends like Zenmap are available. Nmap’s ability to provide detailed information about networked devices makes it ideal for security auditing and network mapping.

3. Nikto

Nikto is an open-source web server scanner that performs comprehensive tests against web servers for multiple items, including over 6,700 potentially dangerous files and programs. It checks for outdated versions of servers, identifying server misconfigurations and security issues. 

Nikto is straightforward to use with a simple command-line interface, making it accessible for quick scans. However, its focus on known issues means it might miss more complex vulnerabilities, and it can generate a high number of false positives, requiring manual verification. Nikto is best suited for web server administrators who need a quick, thorough check of their server’s security posture and can handle its simplicity and potential for false positives.

4. OpenVAS (Open Vulnerability Assessment System)

OpenVAS is an open-source framework for network vulnerability scanning. It is known for its extensive vulnerability database, which is regularly updated to include the latest threat information. OpenVAS provides detailed reports that include the vulnerabilities’ severity and remediation recommendations. It can be integrated with various other security tools, making it a versatile choice for security professionals. 

OpenVAS enables scanning large networks due to its scalability and thorough scanning capabilities. However, its setup can be complex, especially for beginners. OpenVAS is best suited for organizations needing detailed and comprehensive network vulnerability management.

5. Wapiti

Wapiti is an open-source web application vulnerability scanner used to detect security vulnerabilities within web applications. It analyzes the structure of web applications and attempts to identify potential weaknesses that attackers could exploit. Wapiti performs various types of tests, including SQL injection, cross-site scripting (XSS), remote file inclusion, and other common vulnerabilities.

The highly configurable tool allows users to customize the scanning process based on their specific requirements. Wapiti generates detailed reports outlining the discovered vulnerabilities, including their severity levels and recommendations for remediation. Its versatility, ease of use, and active development community make Wapiti a valuable asset for organizations seeking to enhance the security of their web applications.

6. Tenable Nessus Essentials

Tenable Nessus Essentials is a free version of the well-known Nessus vulnerability scanner designed for personal, non-commercial use. It allows users to scan up to 16 IP addresses, making it suitable for small networks or individual use. Nessus Essentials provides comprehensive scanning capabilities, identifying a wide range of vulnerabilities, misconfigurations, and compliance issues.

Its user-friendly interface makes it easy to set up and use, even for those with limited security expertise. The web vulnerability scanner is regularly updated to ensure its vulnerability database is current. However, its free version is limited to a small number of IP addresses and lacks some of the advanced features found in the commercial version, such as extensive reporting and integration capabilities. It is best suited for personal use or small-scale security assessments.

7. Burp Suite Community Edition

Burp Suite Community Edition is a free, limited version of the widely used Burp Suite Professional. It is ideal for manual web application security testing and offers essential tools such as an intercepting proxy, spidering to discover application structure and basic scanning for common vulnerabilities. 

The Community Edition is favored by security enthusiasts and professionals for its reliability and effectiveness in manual testing scenarios. It provides detailed insight into the HTTP/S traffic, allowing testers to manipulate requests and responses to uncover security issues. 

However, the community edition lacks the automation and advanced features of the Professional Edition, such as advanced scanning capabilities and the ability to save work. This makes it less suitable for extensive or long-term projects but good for learning and conducting manual web security tests. Burp Suite can also be considered as part of pentesting tools.

FAQ: Open Source Vulnerability Scanning Tools