CVE-2026-39977 — Path Traversal in Flatpak-builder

CWE-22 — Path Traversal7 documents6 sources
Severity
7.1HIGHNVD
EPSS
0.1%
top 81.03%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
1
Flatpak Flatpak-builder
Timeline
PublishedApr 9
Latest updateApr 13

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 on…

CVSS vector

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

Affected Packages1 packages

▶CVEListV5flatpak/flatpak-builder>= 1.4.5, < 1.4.8

🔴Vulnerability Details

2
VulDB
flatpak -builder up to 1.4.7 g_file_resolve_relative_path path traversal↗2026-04-09
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CVEList
flatpak-builder has a path traversal leading to arbitrary file read on host when installing licence files↗2026-04-09
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📋Vendor Advisories

1
Red Hat
flatpak-builder: path traversal leading to arbitrary file read on host when installing licence files↗2026-04-09
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🕵️Threat Intelligence

1
Wiz
CVE-2026-39977 Impact, Exploitability, and Mitigation Steps | Wiz↗
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💬Community

2
Bugzilla
CVE-2026-39977 flatpak-builder: path traversal leading to arbitrary file read on host when installing licence files [fedora-all]↗2026-04-13
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Bugzilla
CVE-2026-39977 flatpak-builder: path traversal leading to arbitrary file read on host when installing licence files↗2026-04-09
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CVE-2026-39977 — Path Traversal in Flatpak-builder | cvebase