Executive brief
Incus is a system container and virtual machine manager used to deploy and manage isolated workloads. A flaw in the copy-across-projects feature allows an attacker with view access to an unrestricted instance and create permissions in a restricted project to bypass project security policies, gaining privileged container access and potentially escaping to the host system.
Technical details
The vulnerability is an authorization bypass (CWE-863) in the cross-project instance copy path. When copying an instance from a source project to a target project, the AllowInstanceCreation check runs before the source instance's configuration is merged into the request. After the check passes, dangerous configuration keys (security.privileged, raw.lxc, raw.apparmor) from the source instance are merged into the target instance configuration, bypassing project-level restrictions. An attacker with CanView permission on a source instance in an unrestricted project and CanCreateInstances permission in a restricted target project can exploit this by copying a privileged instance across projects, resulting in a fully escaped privileged container. The fix, available in version 7.3.0, adds a post-merge restriction check similar to the existing one in the backup restore code path.
Affected products
- Canonical Incus prior to 7.3.0
Timeline
- 2026-07-30: disclosed
- 2026-07-30: patched: Version 7.3.0 released with fix
- 2026-08-21: advisory