Vulnerability · Published Apr 9, 2026 · Assigned by canonical
CVE-2026-34178Importing a crafted backup leads to project restriction bypass
Critical 9.1
In plain English
A critical-severity improper input validation in lxd from Canonical. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | incus | 6.0.4-2+deb13u6 | DEBIAN-CVE-2026-34178 |
| Debian:14 | incus | 6.0.6-3 | DEBIAN-CVE-2026-34178 |
| Debian:12 | lxd | no fix listed | DEBIAN-CVE-2026-34178 |
| Debian:13 | lxd | 5.0.2+git20231211.1364ae4-9+deb13u5 | DEBIAN-CVE-2026-34178 |
| Go | github.com/canonical/lxd | no fix listed | GHSA-q96j-3fmm-7fv4 |
| Go | github.com/canonical/lxd | no fix listed | GO-2026-5576 |
| Ubuntu:25.10 | incus | no fix listed | UBUNTU-CVE-2026-34178 |
| Ubuntu:26.10 | incus | no fix listed | UBUNTU-CVE-2026-34178 |
Affected products (as reported)
Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
References
- Importing a crafted backup leads to project restriction bypass vdb-entry, vendor-advisory
- Import: Create backup config from index patch, issue-tracking