Yes there is security screening, because you arrive in arrivals level, and need to go to departure.
If you don't have boarding passes printed out, or on your phones, you will have to go to the UO transfer desk to get them before going through the security check.
Note that most (but not all) UO flights now leave from the Mid Field Concourse, not Terminal 1, so you will need to get the train/ people mover from T1 to MFC. Although the flight on the 26th left from the North Satellite Concourse, which is a short bus ride from Terminal 1.
883 has been arriving on time/ early these last few days, so should be OK.