Auth bypass in Canonical Lxd
CVE-2026-9640
A privilege escalation vulnerability exists in LXD from 6.0 before 6.9, 5.21.0 before 5.21.5, and 5.0.0 before 5.0.7 regarding the handling of project-restriction policies during snapshot restoration.. An authenticated project operator in a restricted multi-tenant environment can bypass policy restrictions by importing a maliciously crafted instance backup containing restricted configuration keys within a snapshot. When the snapshot is restored, these restricted keys are applied to the live instance without policy validation. Starting the modified instance grants the operator unauthorized host root access.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Canonical Lxd — versions 5.21.0, 5.0.0, 6.0
Weakness classification (CWE)
References
- github.com/canonical/lxd/security/advisories/GHSA-ppq7-4492-5552 (Exploit, vendor-advisory, vdb-entry)
- github.com/canonical/lxd/pull/18301 (Patch, patch, Issue Tracking)
- github.com/canonical/lxd/pull/18303 (Patch, patch, Issue Tracking)
- github.com/canonical/lxd/pull/18304 (Patch, patch, Issue Tracking)
Frequently asked questions
- What is CVE-2026-9640?
- CVE-2026-9640 is a high-severity vulnerability in Canonical Lxd, classified under Incorrect Authorization. CVSS score: 7.2/10. Published 2026-06-26.
- How severe is CVE-2026-9640?
- High severity. CVSS v3 base score is 7.2 out of 10.