Prototype pollution via unchecked __proto__ key traversal

Prototype pollution in Luke Edwards nestie 0.0.0 through 1.0.0 allows attackers to modify Object.prototype via crafted flattened keys. The nestie function walks each dot-delimited key and follows the inherited proto property instead of rejecting it, so a later assignment writes an attacker-controlled property onto the shared prototype. Exploitation requires an application to pass attacker-controlled keys into the library; polluted properties can crash the process, while remote code execution depends on a separate application-specific gadget.