Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.

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Fixes

Solution

Upgrade to LXD versions 4.0.14, 5.0.10, 5.21.8, 6.10 or later.


Workaround

No workaround given by the vendor.

History

Mon, 28 Sep 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Canonical
Canonical lxd
Vendors & Products Canonical
Canonical lxd

Mon, 28 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 28 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Description Path traversal in the Btrfs storage driver (unpackVolume) in Canonical LXD on Linux allows an authenticated user with instance creation privileges to delete or replace arbitrary files and directories on the host filesystem as root via a crafted subvolumes[].path entry in backup/optimized_header.yaml during a btrfs optimized backup import.
Title Path traversal via Btrfs optimized-backup subvolumes[].path enables root file/dir manipulation in LXD
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: canonical

Published:

Updated: 2026-09-28T13:53:42.731Z

Reserved: 2026-09-04T08:34:29.842Z

Link: CVE-2026-85526

cve-icon Vulnrichment

Updated: 2026-09-28T13:53:38.667Z

cve-icon NVD

Status : Deferred

Published: 2026-09-28T14:17:20.423

Modified: 2026-09-28T15:12:32.657

Link: CVE-2026-85526

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-28T15:30:02Z

Weaknesses