Critical severity · published Sep 28, 2026
CVE-2026-85526
Path traversal via Btrfs optimized-backup subvolumes[].path enables root file/dir manipulation in LXD
9.9
CVSS
0.5%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LX
LXD · Canonical
4.0.0 before 4.0.14; 5.0.0 before 5.0.10; 5.21.0 before 5.21.8; 6.0 before 6.10 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85526
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-85526
vendor-advisory
https://github.com/canonical/lxd/security/advisories/GHSA-h85r-gjgx-g2rv
patch
https://github.com/canonical/lxd-private/pull/87
patch
https://github.com/canonical/lxd-private/pull/105
patch
https://github.com/canonical/lxd-private/pull/104
patch
https://github.com/canonical/lxd-private/pull/103
patch
https://github.com/canonical/lxd-private/pull/84
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