Please report it privately, by email to marcomorosi.dev@gmail.com, with a subject that starts with [SECURITY ISSUE]. Say what you found, how to see it happen, and the version of the app. Please do not open a public issue for it.

FFmpeg GUI is made by one person in spare time: you will get an answer as soon as possible. Once a fix is released, it is named in the release notes, with your name if you wish.

FFmpeg GUI is in alpha: only the latest release gets fixes.

• No network. The app has no internet permission (the build fails if any network permission ever appears in it), so nothing it opens can be sent anywhere by it.
• Only the files you give it. No storage, media, camera or microphone permission: it sees only what you open with the system's picker or share to it, and its own files. Files handed over by other apps are taken only as those apps' content, never as a path to the app's own files.
• No shell. FFmpeg runs inside the app with a list of arguments, never through a shell: a command written by hand cannot start other programs. FFmpeg's filters that load plugin libraries are not built in.
• Checked downloads. The FFmpeg runtime is built from sources pinned by commit and checked by hash (see docs/BUILDING.md); the AI models are checked by SHA-256 when they are imported, wherever their authors publish one.

The FFmpeg runtime is FFmpegKitNext 6.1.1 (FFmpeg 6.1.6). Some of the libraries it bundles are older than their latest releases, which fix known vulnerabilities in the reading of media and font files. Meanwhile, beyond the limits above, fonts embedded in subtitle files are discarded before subtitles are burnt in (fonts are picked in the app instead).

The runtime will move to FFmpegKitNext 7.1 before the app leaves alpha.

As with any media app processing complex file formats, always prefer files from sources you trust.