Path traversal in LXD - CVE-2026-66898
Published: August 1, 2026
Vulnerability identifier: #VU140673
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-2026-66898
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to path traversal in createFromBackup during instance backup restore when processing an application/octet-stream instance backup import request. A remote user can supply a crafted backup tarball with a traversal sequence in backup/index.yaml to execute arbitrary code.
The issue is reachable through POST /1.0/instances, and snapshot names in the backup metadata are described as a second identical vector.
Affected software
LXD
How to mitigate CVE-2026-66898
Install security update from vendor's website.
LXD - addressed in versions 4.0.12, 5.0.4, 5.21.2, 6.1