Path Traversal in Canonical Lxd
CVE-2026-85526
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv (issue-tracking, vendor-advisory)
- github.com/canonical/lxd-private/pull/87 (patch)
- github.com/canonical/lxd-private/pull/105 (patch)
- github.com/canonical/lxd-private/pull/104 (patch)
- github.com/canonical/lxd-private/pull/103 (patch)
- github.com/canonical/lxd-private/pull/84 (patch)
Frequently asked questions
- What is CVE-2026-85526?
- CVE-2026-85526 is a critical-severity vulnerability in Canonical Lxd, classified under Path Traversal. CVSS score: 9.9/10. Published 2026-09-28.
- How severe is CVE-2026-85526?
- Critical severity. CVSS v3 base score is 9.9 out of 10.