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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.53% probability · 44th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Source
- security@ubuntu.com
EPSS moved from 0.5% on 29 September 2026 to 0.5% on 26 October 2026.
References
- https://github.com/canonical/lxd-private/pull/103
- https://github.com/canonical/lxd-private/pull/104
- https://github.com/canonical/lxd-private/pull/105
- https://github.com/canonical/lxd-private/pull/84
- https://github.com/canonical/lxd-private/pull/87
- https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.