CVE-2026-66898

Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE

Published Aug 12, 2026 CVSS 3.1 · 9.9 Critical EPSS < 1% KEV · Not listed
Description
A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.

Remediation

Vendor Solution

Upgrade to LXD version 4.0.12 or later, 5.0.4 or later, or 5.12.2 or later, or 6.0 or later.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*
cpe:2.3:a:canonical:lxd:6.0:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Canonical
Canonical lxd
Vendors & Products Canonical
Canonical lxd
Type Values Removed Values Added
Description A path traversal vulnerability in LXD allows an attacker to manipulate file system paths during backup import and restore operations. When importing or restoring a backup archive, LXD fails to validate instance and storage volume names contained within the archive metadata. An attacker can exploit this flaw by supplying a crafted backup archive with malicious instance or volume names containing path traversal sequences, potentially allowing file access or overwriting outside the designated restore directory.
Title Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
canonical
Published
Updated
Aug 13, 2026, 1:40 PM
Reserved
Jul 28, 2026, 7:41 AM
Status
Analyzed
Published
Aug 12, 2026, 9:17 PM
Modified
Oct 24, 2026, 4:10 PM