25 open-source cybersecurity tools that don’t care about your budget

Regardless of the operating system you use, managing secrets, apps, cloud, compliance, and security operations can be overwhelming. The free, open-source tools presented in this article can help you detect threats, increase visibility, enforce controls, and investigate and respond to incidents throughout the development and operational lifecycle.

Allama: Open-source AI security automation

Allama is an open-source security automation platform that lets teams build visual workflows for threat detection and response. It includes integrations with 80+ types of tools and services typical in security operations, including SIEM systems, endpoint detection and response products, identity providers, and ticketing systems.

Anubis: Open-source web AI firewall to protect from scraper bots

Anubis is an open-source tool designed to protect websites from automated scraping and abusive traffic by adding computational friction before a request is served. Maintained by TecharoHQ, the project targets a growing problem for site operators who want to keep content accessible to humans while limiting large scale automated collection.

Asqav: Open-source SDK for AI agent governance

AI agents are executing consequential tasks autonomously, often across multiple systems and with little record of what they did or why. Asqav, a Python SDK released under the MIT license, addresses that gap by attaching a cryptographic signature to each agent action and linking entries into a hash chain.

Bandit: Open-source tool designed to find security issues in Python code

Bandit is an open-source tool that scans Python source code for security issues that show up in everyday development. Many security teams and developers use it as a quick way to spot risky coding patterns early in the lifecycle, especially in projects that already rely on automated linting and testing.

Betterleaks: Open-source secrets scanner

Secrets scanning has become standard practice across engineering organizations, and Gitleaks has been one of the most widely used tools in that space. Zach Rice, the author of that project has now released a new tool called Betterleaks, which is designed to scan git repositories, directories, and standard input for leaked credentials, API keys, tokens, and passwords.

Brakeman: Open-source vulnerability scanner for Ruby on Rails applications

Brakeman is an open-source security scanner used by teams that build applications with Ruby on Rails. The tool focuses on application code and configuration, giving developers and security teams a way to identify common classes of web application risk during development and testing.

Brutus: Open-source credential testing tool for offensive security

Brutus is an open-source, multi-protocol credential testing tool written in pure Go. Designed to replace legacy tools that have long frustrated penetration testers with dependency headaches and integration gaps, Brutus ships as a single binary with zero external dependencies and native support for the JSON-based reconnaissance pipelines that define offensive security.

CERT UEFI Parser: Open-source tool exposes UEFI architecture to uncover vulnerabilities

CERT UEFI Parser, a new open-source security analysis tool from the CERT Coordination Center has been released to help researchers and defenders examine the structure of Unified Extensible Firmware Interface (UEFI) software and identify classes of vulnerabilities that are often difficult to study.

Cloud-audit: Fast, open-source AWS security scanner

Running AWS security audits without a dedicated security team typically means choosing between enterprise platforms with per-check billing and generic open-source scanners that produce findings with no remediation guidance. Cloud-audit, a Python CLI tool published on GitHub by Mariusz Gebala, takes a narrower scope and attaches a fix to every finding it generates.

Comp AI: The open-source way to get compliant with SOC 2, ISO 27001, HIPAA and GDPR

Comp AI is an open-source compliance platform targeting SOC 2, ISO 27001, HIPAA, and GDPR. It automates evidence collection, policy management, and control implementation, and it positions itself as a direct alternative to established vendors Vanta and Drata.

Conjur: Open-source secrets management and application identity

Conjur is an open-source secrets management project designed for environments built around containers, automation, and dynamic infrastructure. It focuses on controlling access to credentials such as database passwords, API keys, and tokens that applications need at runtime. The project is maintained in the open and developed with input from a user and contributor base.

Little Snitch for Linux shows what your apps are connecting to

Network monitoring on Linux has long been a gap for users who want per-process visibility into outbound connections. Existing tools either operate at the command line or were designed for server security rather than desktop privacy. Objective Development, the Austrian company behind the macOS firewall utility Little Snitch, released a Linux version of the tool. It is free and, according to the company, will remain so.

mquire: Open-source Linux memory forensics tool

Linux memory forensics has long depended on debug symbols tied to specific kernel versions. These symbols are not installed on production systems by default, and sourcing them from external repositories creates a recurring problem: repositories go stale, kernel builds diverge, and analysts working incident response often find no published symbols for the exact kernel they need to examine. Trail of Bits published mquire to address this constraint. The open-source tool analyzes Linux memory dumps without requiring any external debug information.

OpenAEV: Open-source adversarial exposure validation platform

OpenAEV is an open source platform designed to plan, run, and review cyber adversary simulation campaigns used by security teams. The project focuses on organizing exercises that blend technical actions with operational and human response elements, all managed through a single system.

OpenClaw Scanner: Open-source tool detects autonomous AI agents

A new free, open source tool is available to help organizations detect where autonomous AI agents are operating across corporate environments. The OpenClaw Scanner identifies instances of OpenClaw, an autonomous AI assistant also known as MoltBot, that can execute tasks, access local files, and authenticate to internal systems without centralized oversight.

Open-source tool Sage puts a security layer between AI agents and the OS

Autonomous AI agents running on developer workstations execute shell commands, fetch URLs, and write files with little or no inspection of what they are doing. Open-source project Sage inserts an interception layer between an AI agent and those operations, checking each action before it proceeds.

pfSense: Open-source firewall and routing platform

Firewalls, VPN access, and traffic rules need steady attention, often with limited budgets and staff. In that context, the open source pfSense Community Edition (CE) continues to show up in production environments, supported by a long-standing user community. pfSense CE is the free, open-source version of the pfSense firewall and routing platform. The software runs on standard x86 hardware, virtual machines, and some embedded systems, which keeps deployment flexible for small teams and labs.

Plumber: Open-source scanner of GitLab CI/CD pipelines for compliance gaps

GitLab CI/CD pipelines often accumulate configuration decisions that drift from security baselines over time. Container images get pinned to mutable tags, branches lose protection settings, and required templates go missing. An open-source tool called Plumber automates the detection of those conditions by scanning pipeline configuration and repository settings directly.

Pompelmi: Open-source secure file upload scanning for Node.js

Software teams building services in JavaScript are adding more layers of defense to handle untrusted file uploads. An open-source project called Pompelmi aims to insert malware scanning and policy checks directly into Node.js applications before files reach storage or business logic. It is built for JavaScript and TypeScript environments and runs directly within the application process. Files are scanned in memory at upload time, allowing applications to make accept or reject decisions early in the request flow.

Prometheus: Open-source metrics and monitoring systems and services

Prometheus is an open-source monitoring and alerting system built for environments where services change often and failures can spread fast. For security teams and DevOps engineers, it has become a common way to track system behavior, spot early warning signs, and understand what is happening across large sets of workloads.

Scenario: Open-source framework for automated AI app red-teaming

Enterprises running customer service bots, data analytics agents, and other AI-driven applications in production handle sensitive records and connect to core business systems every day. LangWatch has released Scenario, an open-source framework that runs automated red-team exercises against AI agents using multi-turn attack techniques that mirror how adversaries operate in the wild.

SecureClaw: Dual stack open-source security plugin and skill for OpenClaw

SecureClaw is an open-source project that adds security auditing and rule-based controls to OpenClaw agent environments. The tool is published by Adversa AI and is designed to work with OpenClaw and related agents such as Moltbot and Clawdbot.

ShipSec Studio brings open-source workflow orchestration to security operations

Security teams have long relied on a mix of shell scripts, cron jobs, and loosely connected tools to chain reconnaissance and vulnerability scanning work together. ShipSec Studio, an open-source security workflow automation platform from ShipSec AI, aims to replace that arrangement with a dedicated orchestration layer built specifically for security operations.

StackRox: Open-source Kubernetes security platform

The StackRox open source platform focuses on Kubernetes and container security across the build and runtime lifecycle. It ingests data from container images, Kubernetes APIs, and runtime activity inside clusters. That data feeds policy checks tied to configuration, vulnerability data, and observed behavior.

Zabbix: Open-source IT and OT observability solution

Zabbix is an open source monitoring platform designed to track the availability, performance, and integrity of IT environments. It monitors networks along with servers, virtual machines, applications, services, databases, websites, and cloud resources.

Must read:

• 40 open-source tools redefining how security teams secure the stack
• 35 open-source security tools to power your red team, SOC, and cloud security

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