CVE-2026-85526

Published: Sep 28, 2026Modified: Sep 29, 2026Deferred

9.9

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitability: 3.1 / Impact: 6.0

Source: security@ubuntu.com (Secondary)

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.

Related CWEs

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

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

References (6)

https://github.com/canonical/lxd-private/pull/103

Source: security@ubuntu.com

https://github.com/canonical/lxd-private/pull/104

Source: security@ubuntu.com

https://github.com/canonical/lxd-private/pull/105

Source: security@ubuntu.com

https://github.com/canonical/lxd-private/pull/84

Source: security@ubuntu.com

https://github.com/canonical/lxd-private/pull/87

Source: security@ubuntu.com

https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv

Source: security@ubuntu.com

Timeline

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