CVE-2026-39977
Last modified
CVE-2026-39977 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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. EPSS estimates a 0.29% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Flatpak | Flatpak-Builder | >= 1.4.5, < 1.4.8 |
References
- https://github.com/flatpak/flatpak-builder/security/advisories/GHSA-6gm9-3g7m-3965Exploit, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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