CVE-2026-46510: Prototype Pollution Via In Operator

Checking property existence with the `in` operator can lead to prototype pollution when dealing with user-controlled keys. The `in` operator traverses the prototype chain and evaluates to true for internal properties like `__proto__` and `constructor`. If the property is then extracted and modified, it can pollute the global object prototype. Replace `in` wi

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Description

Checking property existence with the `in` operator can lead to prototype pollution when dealing with user-controlled keys. The `in` operator traverses the prototype chain and evaluates to true for internal properties like `__proto__` and `constructor`. If the property is then extracted and modified, it can pollute the global object prototype. Replace `in` wi