by Kastro
Paper/Archive/CVE-2026-34178

CVE-2026-34178

Canonical lxd — Importing a crafted backup leads to project restriction bypass

EPSS 0.4%public exploitCVSS 9.1
critical.is priorityof 100
45
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 36.8.368 × 207.4Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
lxd4.12.0 – < 5.0.75.0.7CNA
lxd5.1.0 – < 5.21.55.21.5CNA
lxd6.0.0 – < 6.8.06.8.0CNA

Scores by source

canonical (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/canonical/lxd/security/advisories/GHSA-q96j-3fmm-7fv4patchgithub.com/canonical/lxd/pull/17921