Vulnerability Description
Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of keys blocked under the restricted.virtual-machines.lowlevel=block project restriction. A remote attacker with can_edit permission on a VM instance in a restricted project can inject an AppArmor rule and a QEMU chardev configuration that bridges the LXD Unix socket into the guest VM, enabling privilege escalation to LXD cluster administrator and subsequently to host root.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Canonical | Lxd | >= 4.12, <= 5.0.6 |
Related Weaknesses (CWE)
References
- https://github.com/canonical/lxd/pull/17909Issue Tracking
- https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6fThird Party Advisory
- https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6fThird Party Advisory
FAQ
What is CVE-2026-34177?
CVE-2026-34177 is a vulnerability with a CVSS score of 9.1 (CRITICAL). Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of ke...
How severe is CVE-2026-34177?
CVE-2026-34177 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-34177?
Check the references section above for vendor advisories and patch information. Affected products include: Canonical Lxd.