CVE catalog
CVE-2026-39977
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 directo
- Severity
- High · CVSS 7.1
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 - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.29% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | flatpak-builder | sid | 1.4.12-2 | fixed |
| Debian | flatpak-builder | forky | 1.4.12-2 | fixed |
| Debian | flatpak-builder | trixie | 1.4.4-2 | not affected |
| Debian | flatpak-builder | bookworm | 1.2.3-1 | not affected |
| Cpe | flatpak-builder | Not reported | 1.4.8 | fixed |
| Ubuntu | flatpak-builder | 25.10 | 1.4.4-2 | vulnerable |
| Ubuntu | flatpak-builder | 25.10 | 1.4.4-2build1 | vulnerable |
| Ubuntu | flatpak-builder | 25.10 | 1.4.5-1 | vulnerable |
| Ubuntu | flatpak-builder | 25.10 | 1.4.6-2 | vulnerable |
| Ubuntu | flatpak-builder | 26.04 | 1.4.6-2 | vulnerable |
| Ubuntu | flatpak-builder | 26.04 | 1.4.7-1 | vulnerable |
| Ubuntu | flatpak-builder | 26.04 | 1.4.8-1 | fixed |
| Opensuse | flatpak-builder | tumbleweed | 1.4.8-1.1 | fixed |
| Cpe | flatpak-builder | Not reported | 1.4.8 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | flatpak-builder | source | sid | 1.4.8-1 | not yet assigned | Not reported | [1133099] |
| Debian | flatpak-builder | source | forky | 1.4.8-1 | not yet assigned | Not reported | [1133099] |
| Debian | flatpak-builder | source | trixie | Not affected | unimportant | Not reported | [1133099] |
| Debian | flatpak-builder | source | bookworm | Not affected | unimportant | Not reported | [1133099] |
| Cpe | flatpak-builder | cpe | Not reported | 1.4.8 | Not reported | Not reported | Not reported |
| Ubuntu | flatpak-builder | deb | 26.04 | 1.4.8-1 | Not reported | UBUNTU-CVE-2026-39977 | Not reported |
| Opensuse | flatpak-builder | rpm | tumbleweed | 1.4.8-1.1 | Not reported | OPENSUSE-SU-2026:10590-1 | Not reported |
| Cpe | flatpak-builder | cpe | Not reported | 1.4.8 | Not reported | NVD-CVE-2026-39977 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [flatpak-builder]Not affected
Details (4)
1.2.3-1· amd64 · bookwormNot affected
nvd · flatpak-builder · debian · bookworm
1.2.3-1· arm64 · bookwormNot affected
nvd · flatpak-builder · debian · bookworm
1.4.4-1~bpo12+1· amd64 · bookworm-backportsNot affected
nvd · flatpak-builder · debian · bookworm
1.4.4-1~bpo12+1· arm64 · bookworm-backportsNot affected
nvd · flatpak-builder · debian · bookworm
- [flatpak-builder-tests]Not affected
Source package: [flatpak-builder]
Details (4)
1.2.3-1· amd64 · bookwormNot affected
nvd · flatpak-builder · debian · bookworm
1.2.3-1· arm64 · bookwormNot affected
nvd · flatpak-builder · debian · bookworm
1.4.4-1~bpo12+1· amd64 · bookworm-backportsNot affected
nvd · flatpak-builder · debian · bookworm
1.4.4-1~bpo12+1· arm64 · bookworm-backportsNot affected
nvd · flatpak-builder · debian · bookworm
[openSUSE Tumbleweed]
- [flatpak-builder]Fixed
Source package: [flatpak-builder]
Details (1)
1.4.10-1.1· x86_64 · tumbleweedFixed · Fixed:
1.4.8-1.1nvd · flatpak-builder · opensuse · tumbleweed
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_10590-1.json]
- [https://github.com/flatpak/flatpak-builder/security/advisories/GHSA-6gm9-3g7m-3965]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-39977]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-39977]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-39977]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:10590-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-39977]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39977.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]