Open-source Palo Alto Networks alternatives

Kubescape is an open-source Kubernetes security platform that covers the lifecycle from development to runtime. It was created by ARMO and is a Cloud Native Computing Foundation incubating project. It works in an IDE, in CI/CD pipelines and against running clusters, with the aim of saving administrators time on risk analysis and compliance work.

Misconfiguration scanning checks clusters, YAML files and Helm charts against NSA-CISA guidance, MITRE ATT&CK and CIS Benchmarks. Image vulnerability scanning detects CVEs using Grype, image patching uses Copacetic, and auto-remediation can fix manifest issues. Admission control uses Validating Admission Policies, runtime monitoring is eBPF-based through Inspektor Gadget, and an MCP server connects AI assistants.

Kubescape is written in Go and released under the Apache-2.0 license. It installs through options such as Homebrew and Krew, and an in-cluster operator is available for continuous scanning. Results include an overview of control plane status, access control risks, workload misconfigurations, network policy gaps and compliance scores.

Falco is a cloud native runtime security tool for Linux. It detects and alerts on abnormal behavior and potential security threats in real time. At its core it is a kernel monitoring and detection agent that watches events such as system calls and evaluates them against custom rules.

Falco can enrich events with metadata from the container runtime and from Kubernetes, and the collected events can be analyzed off-host in SIEM or data lake systems. The project is split across repositories in the falcosecurity organization: the main repo holds the Falco binary, while others hold the core libraries and kernel drivers, the official ruleset, and plugins that extend detection beyond syscalls and container events.

Falco was originally created by Sysdig and is a graduated project of the Cloud Native Computing Foundation, used in production by various organizations. It is written in C++ and released under the Apache-2.0 license, with a change log and detailed documentation on falco.org. Topics in the repository mention eBPF-based collection.

Suricata is an engine for network intrusion detection (IDS), intrusion prevention (IPS) and network security monitoring (NSM), developed by the Open Information Security Foundation and the Suricata community. It inspects network traffic to detect threats, can block them when run inline as an intrusion prevention system, and supports network security monitoring and threat hunting.

The README stresses why the software is built so carefully. It processes mostly untrusted input and often sits directly reachable by an attacker, so a crash in IPS mode could knock a network offline, a compromise in passive mode could expose confidential data, and missed detections could hide an intrusion. For that reason contributions go through a long QA process that includes GitHub CI checks, peer review and private QA runs with build tests, static analysis, runtime analysis with valgrind and sanitizers, and regression tests.

Suricata is written in C and licensed under GPL-2.0. The project provides a user guide, an installation guide, a developer guide, a bug tracker and a user support forum for administrators who deploy it on their own networks.

OPNsense is an open-source firewall project, and this repository contains its web GUI, API and systems backend. Its topics point to a broad feature set that includes a firewall, intrusion prevention, proxy, VPN, traffic shaping, a captive portal and routing, built on a BSD base.

The project invites developers to contribute and has designed its build process so that anyone can build and write code. Build tools are freely available in a separate tools repository, an architecture overview is on docs.opnsense.org, and the repository offers Makefile targets such as make package for assembling a package from the current state of the code. The team aims to evolve toward a new codebase gradually rather than in one big switch.

OPNsense is written mostly in PHP and is committed to staying available under the 2-clause BSD license, with every contribution required to carry the same terms. Contributions can be as simple as testing functionality, filing bug reports or sending pull requests.

pfSense is a network firewall distribution built on the FreeBSD operating system. It uses a custom kernel and bundles third-party free software to cover routing and security tasks. The project began in 2004 as a fork of the m0n0wall project and has since diverged significantly.

All components are configured through a web interface, so the project says no UNIX knowledge or command-line work is needed and rule sets never have to be edited by hand. A package system adds functionality, and the project states that with packages it can match or exceed the functionality of common commercial firewalls, without artificial limits. It lists products from Check Point, Cisco, Juniper, Sonicwall, Netgear and Watchguard among those it has replaced.

pfSense is copyright Rubicon Communications (Netgate) and published under an open source license, listed as Apache-2.0 on GitHub. Netgate sells bundled hardware appliances and commercial support, which is the main way the team funds development. Administrators used to commercial firewalls may find the interface familiar, though others face a learning curve.