Path traversal in LXD - CVE-2026-85526
Published: September 25, 2026
Vulnerability identifier: #VU152254
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-85526
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to manipulate arbitrary files and directories on the host.
The vulnerability exists due to improper limitation of a pathname to a restricted directory in the btrfs optimized-backup subvolume path handling when restoring an uploaded backup archive to a btrfs storage pool. A remote user can supply a crafted subvolumes[].path value that escapes the volume mount point to manipulate host filesystem paths as root.
Exploitation requires permission to create instances or storage volumes and a btrfs storage pool.
Affected software
LXD
How to mitigate CVE-2026-85526
Install security update from vendor's website.
LXD - addressed in versions 4.0.14, 5.0.10, 5.21.8, 6.10