Improper access control in LXD - CVE-2026-34177
Published: April 9, 2026
Vulnerability identifier: #VU125587
CSH Severity: Low
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-34177
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges to host root.
The vulnerability exists due to improper access control in isVMLowLevelOptionForbidden in lxd/project/limits/permissions.go when validating VM low-level configuration keys in a restricted project. A remote privileged user can set the raw.apparmor and raw.qemu.conf options on a VM instance to escalate privileges to host root.
Exploitation requires a restricted project with restricted.virtual-machines.lowlevel=block and permission to edit and start a VM instance.
Affected software
LXD
Debian Linux
lxd (Debian package)
Debian Linux
lxd (Debian package)
How to mitigate CVE-2026-34177
Install security update from vendor's website.
LXD - addressed in versions 5.0.7, 5.21.5, 6.8
lxd (Debian package) - addressed in versions 5.0.2+git20231211.1364ae4-9+deb13u5, 5.0.2-5+deb12u5
lxd (Debian package) - addressed in versions 5.0.2+git20231211.1364ae4-9+deb13u5, 5.0.2-5+deb12u5