CVE-2026-34178

Importing a crafted backup leads to project restriction bypass

Published Apr 9, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is never checked against project restrictions. An authenticated remote attacker with instance-creation permission in a restricted project can craft a backup archive where backup.yaml carries restricted settings such as security.privileged=true or raw.lxc directives, bypassing all project restriction enforcement and allowing full host compromise.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6212-1 incus security update
Debian DSA Debian DSA DSA-6213-1 lxd security update
Github GHSA Github GHSA GHSA-q96j-3fmm-7fv4 LXD: Importing a crafted backup leads to project restriction bypass
History
Type Values Removed Values Added
CPEs cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Canonical
Canonical lxd
Vendors & Products Canonical
Canonical lxd
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is never checked against project restrictions. An authenticated remote attacker with instance-creation permission in a restricted project can craft a backup archive where backup.yaml carries restricted settings such as security.privileged=true or raw.lxc directives, bypassing all project restriction enforcement and allowing full host compromise.
Title Importing a crafted backup leads to project restriction bypass
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
canonical
Published
Updated
Apr 9, 2026, 11:55 AM
Reserved
Mar 26, 2026, 9:24 AM
Status
Analyzed
Published
Apr 9, 2026, 10:16 AM
Modified
Oct 26, 2026, 9:10 PM