GHSA-CXMJ-83GH-FP49 MessagePack-CSharp: Multi-dimensional array formatters allocate from unchecked dimensions

Summary MessagePack-CSharp's multi-dimensional array formatters read dimension lengths directly from the payload and allocate T,, T,,, or T,,, before validating that the dimension product matches the encoded element count. The formatter reads a guarded element array header, but allocation of the...