Undefined Behavior

Reading or writing through a null pointer

Using an uninitialized local variable

Accessing an out-of-bounds index

Deleting a derived object via a pointer to a base class that doesnt have a virtual destructor.

Extending the std or posix Namespace

Accessing a dangling reference

Integer division by zero

No return statement for a function with a non-void return type

Invalid pointer arithmetic

Incorrect pairing of memory allocation and deallocation

Signed Integer Overflow

Shifting by an invalid number of positions

Modifying a const object

Value of an out-of-range enum

Multiple non-identical definitions the One Definition Rule

Overflow during conversion to or from floating point type

Returning from a noreturn function

Accessing an object as the wrong type

Modifying a string literal