{"id":"DEBIAN-CVE-2026-39977","details":"flatpak-builder is a tool to build flatpaks from source. From 1.4.5 to before 1.4.8, the license-files manifest key takes an array of paths to user defined licence files relative to the source directory of the module. The paths from that array are resolved using g_file_resolve_relative_path() and validated to stay inside the source directory using two checks - g_file_get_relative_path() which does not resolve symlinks and g_file_query_file_type() with G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS which only applies to the final path component. The copy operation runs on host. This can be exploited by using a crafted manifest and/or source to read arbitrary files from the host and capture them into the build output. This vulnerability is fixed in 1.4.8.","modified":"2026-09-14T17:03:32.087419266Z","published":"2026-04-09T20:16:26.660Z","upstream":["CVE-2026-39977"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-39977"}],"affected":[{"package":{"name":"flatpak-builder","ecosystem":"Debian:14","purl":"pkg:deb/debian/flatpak-builder?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.8-1"}]}],"versions":["1.4.4-2","1.4.5-1","1.4.6-1","1.4.6-2","1.4.7-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-39977.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"}]}