OWASP Threat Dragon

OWASP Threat Dragon is a free, open-source, cross-platform threat modeling application. Teams use it to draw data-flow diagrams, list threats for diagram elements, and record mitigations and countermeasures. The project emphasizes accessible, flexible threat modeling and follows the threat modeling manifesto.

The desktop application stores threat model files on the local filesystem. This differs from the separately deployed web application, which can be configured to access GitHub, Bitbucket, GitLab, and GitHub Enterprise repositories. Desktop installers are provided for macOS, Windows, and Linux under the Apache 2.0 license.

This Homebrew cask installs Threat-Dragon-ng.app. On macOS, the upstream release recommends the architecture-specific DMG installer; ZIP archives are used for automatic updates rather than initial installation. Version 2.x is the maintained Vue-based line; the older AngularJS-based 1.x line is in maintenance mode.

Official sources: https://github.com/OWASP/threat-dragon and https://owasp.org/projects/threat-dragon