Sebastian Wick
b24b3b2485
The runtime files directory was opened with open() using O_PATH but without symlink protection, unlike the app files path which used O_NOFOLLOW. Since "files" is validated as a non-symlink during deploy, this is not exploitable through normal install flow. However, the open should still use safe fd-relative operations as defense-in-depth. Use flatpak_deploy_get_files_fd which validates the path with glnx_chaseat(GLNX_CHASE_RESOLVE_NO_SYMLINKS), rejecting any symlink at the directory boundary. Hardening related to CVE-2026-97023, CVE-2026-97024 Helps: https://github.com/flatpak/flatpak/security/advisories/GHSA-5p67-xh8x-rq54 Helps: https://github.com/flatpak/flatpak/security/advisories/GHSA-8xgq-v545-vgvf
Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux.
See https://flatpak.org/ for more information.
Flatpak is available in the package repositories of most Linux distributions and can be installed from there. See https://flatpak.org/setup/ for quick setup instructions for many distributions.
Community discussion happens in #flatpak:matrix.org, on the mailing list, and on the Flathub Discourse.
Read documentation for Flatpak here.
Contributing
Flatpak welcomes contributions from anyone! Here are some ways you can help:
- Fix one of the issues and submit a PR
- Update flatpak's translations
- Improve flatpak's documentation, hosted at http://docs.flatpak.org and developed over in flatpak-docs
- Find a bug and submit a detailed report including your OS, flatpak version, and the steps to reproduce
- Add your favorite application to Flathub by writing a flatpak-builder manifest and submitting it
- Improve the Flatpak support in your favorite Linux distribution
Hacking
See CONTRIBUTING.md
Related Projects
Here are some notable projects in the Flatpak ecosystem:
- Flatseal: An app for managing permissions of Flatpak apps without using the CLI
- Flat-manager: A tool for managing Flatpak repositories
Host Requirements
Flatpak aims to run on a wide variety of systems. It is therefore conservative with required dependency versions and kernel features.
Currently, the main branch requires at least kernel version 5.8 (for
statx STATX_MNT_ID).