Path traversal in LXD - CVE-2026-16033
Published: August 1, 2026
Vulnerability identifier: #VU140674
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-16033
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Affected software:
LXD
LXD
Detailed vulnerability description
The vulnerability allows a remote user to read arbitrary host files and create root-owned files on the host.
The vulnerability exists due to path traversal in the QEMU/VM template path in driver_qemu.go templateApplyNow when processing attacker-controlled template paths from custom VM images or restored VM backups. A remote user can supply crafted metadata.yaml template entries to read arbitrary host files and create root-owned .out files on the host.
The created host file is forced to use a .out suffix, and the file-read result is disclosed into the guest through the VM config drive.
How to mitigate CVE-2026-16033
Install security update from vendor's website.