The root cause of the CWE-190 (Integer Overflow or Wraparound) vulnerability in the given code slice is:

The addition operation on line 13 can potentially lead to an integer overflow. The vulnerability occurs because there's no check to ensure that adding `ticks_from_now` to the current time (`ble_npl_time_get()`) won't result in an overflow of the `abs_time` variable.

Specifically:

1. `ble_npl_time_get()` returns the current time.
2. `ticks_from_now` is an input parameter of type `int32_t`.
3. These values are added together and stored in `abs_time`.

If `ticks_from_now` is a large positive value, and the current time is also large, their sum could exceed the maximum value that can be stored in `abs_time`. This would cause the value to wrap around, resulting in an incorrect and potentially much smaller time value than intended.

To mitigate this vulnerability, the code should include checks to prevent overflow before performing the addition, or use a wider data type that can accommodate larger values without overflowing.