Incus contains a restriction bypass flaw that lets users assigned to restricted projects, when they also have rights to create instances, trigger a cluster‑refresh migration of an existing instance. The resulting refresh request forces the server to open outbound TLS websocket connections, which can be used to probe or communicate with services reachable from the host. This vulnerability does not grant arbitrary code execution but enables attackers to perform internal network reconnaissance or potentially interact with services that would otherwise be inaccessible from within the restricted project. The weakness is identified as CWE‑863 and CWE‑918.

Linux Containers Incus versions 6.0.5 through 6.0.6, 6.12.0 through 7.0.1, and 7.1.0 through 7.4.99 are affected. Any environment running a vulnerable Incus instance with clustered migration enabled is susceptible.

The CVSS score of 5.3 categorises the issue as medium severity. The EPSS score is 0.00365 (≈0.37 %), indicating a low but nonzero probability of exploitation. Incus is not listed in the CISA KEV catalogue. Exploitation requires an attacker to have instance‑creation rights and to target a specific instance with a refresh request. If a cluster node performs the migration, it will establish outbound TLS websocket connections, potentially exposing internal services to the attacker. The attack vector is internal to the cluster but could lead to unintended network traffic from the host.