CVE-2026-114613 MessagePack: Unbounded memory leak in msgpack C extension on strict_map_key validation failure

MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.3, the msgpack-python C extension msgpack.cmsgpack leaks a decoded map value when deserialization rejects a key with strictmapkey=True the default. Repeated malformed inputs can cause unbounded process memory growth...