CVE-2026-34078

Name	CVE-2026-34078
Description	Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the Flatpak portal accepts paths in the sandbox-expose options which can be app-controlled symlinks pointing at arbitrary paths. Flatpak run mounts the resolved host path in the sandbox. This gives apps access to all host files and can be used as a primitive to gain code execution in the host context. This vulnerability is fixed in 1.16.4.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1132943

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
flatpak (PTS)	bullseye	1.10.8-0+deb11u2	vulnerable
	bullseye (security)	1.10.8-0+deb11u3	vulnerable
	bookworm, bookworm (security)	1.14.10-1~deb12u1	vulnerable
	trixie	1.16.3-1~deb13u1	vulnerable
	forky	1.16.3-1	vulnerable
	sid	1.16.4-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
flatpak	source	(unstable)	1.16.4-1			1132943

https://github.com/flatpak/flatpak/security/advisories/GHSA-cc2q-qc34-jprg
Causes regression: https://bugs.debian.org/1132960