Report: Complete Guide to CVE-2026-39977 - flatpak-builder has a path traversal leading to arbitrary file read on host when...
CVE ID :CVE-2026-39977 Published : April 9, 2026, 8:16 p.m. | 51 minutes ago Description :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. Severity: 7.1 | HIGH Visit the link for more details, such as CVSS details, affected products, timeline, and more...