CVE-2026-34078

Flatpak has a complete sandbox escape leading to host file access and code execution in the host context

Published Apr 7, 2026 CVSS 4.0 · 9.3 Critical EPSS 1.7% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6207-1 flatpak security update
Debian DSA Debian DSA DSA-6223-1 flatpak security update
History
Type Values Removed Values Added
CPEs cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H'}

cvssV3_1

{'score': 10.0, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Flatpak
Flatpak flatpak
Vendors & Products Flatpak
Flatpak flatpak
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-59
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
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.
Title Flatpak has a complete sandbox escape leading to host file access and code execution in the host context
Weaknesses CWE-61
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 15, 2026, 1:04 AM
Reserved
Mar 25, 2026, 4:21 PM
Status
Modified
Published
Apr 7, 2026, 10:16 PM
Modified
Jul 24, 2026, 10:10 PM
Severity
Moderate
Public date
Apr 7, 2026, 9:27 PM