Improper access control in LXD - CVE-2026-9640
Published: June 29, 2026
Vulnerability identifier: #VU135806
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-9640
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Containers
Affected software:
LXD
LXD
Detailed vulnerability description
The vulnerability allows a remote user to escalate privileges to arbitrary host root.
The vulnerability exists due to improper access control in the instance-backup import and snapshot-restore handlers when importing a tampered backup and restoring a snapshot. A remote privileged user can upload a crafted instance backup containing restricted snapshot configuration and restore the malicious snapshot to escalate privileges to arbitrary host root.
Exploitation requires a hardened multi-tenant project with restricted=true and restricted.containers.lowlevel=block, and the ability to create instances and edit the target project.
How to mitigate CVE-2026-9640
Install security update from vendor's website.