CVE-2026-96276

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

State: Published
Severity: 6.5 Medium
Published: Sep 23, 2026
Updated: Sep 27, 2026
Reserved: Sep 22, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N	redhat
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	CISA-ADP

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

Product	Versions
Red Hat Enterprise Linux 10Red Hat
Red Hat Enterprise Linux 7Red Hat
Red Hat Enterprise Linux 8Red Hat
Red Hat Enterprise Linux 9Red Hat

References

https://access.redhat.com/security/cve/CVE-2026-96276vdb-entry
RHBZ#2539418issue-tracking
https://github.com/flatpak/flatpak/security/advisories/GHSA-8qxj-x646-phcm

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