Multiple Inheritance from Concrete Classes

While some programming languages support multiple inheritance, this design pattern creates a 'Diamond Problem' where the child class can inherit conflicting method implementations or state from its parents. This leads to fragile, tightly-coupled code that is difficult to reason about, as the behavior of the child class becomes dependent on the complex resolution order of its parent classes. From a security perspective, this complexity directly undermines maintainability. It becomes harder to trace data flow, understand side effects, and audit for vulnerabilities, increasing the time needed to find and fix security flaws. Furthermore, the confusing class hierarchy makes it easier to accidentally introduce new vulnerabilities during maintenance or feature development, as developers may not fully grasp all inherited behaviors.