CVE-2026-96276

Flatpak: flatpak: arbitrary write in host context via flatpak build-init

Published Sep 23, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
If a malicious SDK container declares an extension point with a crafted `directory` path, and a developer runs `flatpak build-init --writable-sdk --sdk-extension` with that SDK, attacker-chosen files could be written outside the working directory, since the target path is resolved via a function that allows `..` traversal.

Remediation

Vendor Workaround

Avoid using an non-trusted SDK for development/compilation.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'}

Type Values Removed Values Added
First Time appeared Flatpak
Flatpak flatpak
Vendors & Products Flatpak
Flatpak flatpak
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

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

Type Values Removed Values Added
Description If a malicious SDK container declares an extension point with a crafted `directory` path, and a developer runs `flatpak build-init --writable-sdk --sdk-extension` with that SDK, attacker-chosen files could be written outside the working directory, since the target path is resolved via a function that allows `..` traversal.
Title Flatpak: flatpak: arbitrary write in host context via flatpak build-init
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-22
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 2:14 AM
Reserved
Sep 22, 2026, 8:42 PM
Status
Awaiting Analysis
Published
Sep 23, 2026, 3:17 PM
Modified
Nov 6, 2026, 3:16 AM