If your vehicle is showing child safety lock stuck engaged preventing rear door from opening, here are the most likely causes and the parts you'll need to fix each one.
The small plastic lever or internal mechanism for the child safety lock inside the door latch assembly has broken or seized, preventing it from being switched off.
The child safety lock intentionally disables the inside handle. If the exterior door handle linkage breaks while the child lock is engaged, the door becomes completely trapped and cannot be opened from either side.
Accumulated dirt, rust, or sticky residue on the door edge can physically jam the child lock toggle switch, preventing it from moving back to the unlocked position.
If work was recently done inside the door panel (like replacing a window regulator or actuator), the metal rods connecting the handles to the latch may be misrouted or binding, preventing the latch from operating properly.