Zenoh uORB Subscriber Allows Arbitrary Stack Allocation

An unbounded stack allocation vulnerability exists in the Zenoh uORB subscriber module of PX4-Autopilot. When handling non-contiguous payloads, the code allocates a variable-length array directly from incoming message size without validation. A remote Zenoh publisher can send an oversized fragmented message to force an unbounded stack allocation and copy, causing a stack overflow and crash or potentially enabling remote code execution.