CVE-2026-85526CWE-22path-traversal

CVE-2026-85526

Critical · published September 28, 2026

CVSS v3.1
9.9
EPSS
1%
Percentile
43.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.9 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00516 · 43.1th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-09-28T18:17Z
References (6)
https://github.com/canonical/lxd-private/pull/103 · [email protected]https://github.com/canonical/lxd-private/pull/104 · [email protected]https://github.com/canonical/lxd-private/pull/105 · [email protected]https://github.com/canonical/lxd-private/pull/84 · [email protected]https://github.com/canonical/lxd-private/pull/87 · [email protected]https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv · [email protected]
EPSS history
Timeline
  • 30 SEP 03:28Z
    EPSS moved — → 1%
    epss
  • 28 SEP 13:21Z
    Path traversal via Btrfs optimized-backup subvolumes[].path enables root file/dir manipulation in LXD
    cvelistv5