Improper Authorization in LXC - CVE-2026-39402
Published: April 30, 2026
Vulnerability identifier: #VU128493
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-39402
CWE-ID: CWE-285
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: lxc
Affected software:
LXC
LXC
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper access control in lxc-user-nic delete authorization logic when deleting OVS-attached network interfaces. A local user can request deletion of another user's OVS port to cause a denial of service.
This is limited to multi-tenant environments using lxc-user-nic with OpenVswitch bridges, and exploitation requires a valid lxc-usernet policy entry on the same bridge.
How to mitigate CVE-2026-39402
Install security update from vendor's website.