CVE-2026-34078

CVE Details

Release Date:	2026-04-07
Impact:	Important	What is this?

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.

See more information about CVE-2026-34078 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	9.0
Vector String:	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	Low
User Interaction:	Required
Scope:	Changed
Confidentiality Impact:	High
Integrity Impact:	High
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (flatpak)	ELSA-2026-21756	2026-05-28