Relative Path Traversal in LXD - CVE-2026-66897
Published: August 25, 2026
Vulnerability identifier: #VU145363
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-2026-66897
CWE-ID: CWE-23
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to write arbitrary files on the host as root.
The vulnerability exists due to path traversal in instance template handling when processing attacker-controlled template target paths from metadata.yaml. A remote user can supply a specially crafted template path to write arbitrary files on the host as root.
No non-default configuration is needed. The issue can be reached through API metadata updates by a user with can_edit permission on a container, and it can also be reached by launching a crafted image.
Affected software
LXD
How to mitigate CVE-2026-66897
Install security update from vendor's website.
LXD - addressed in versions 4.0.13, 5.0.9, 5.21.7, 6.10