There are some scenes of threat, such as those depicting infected zombie-like people attacking the characters, as well as a character trying to escape from large menacing bugs chasing him through underground tunnels.
Three characters are chased and attacked by zombies in a tunnel as they attempt togo through. There are a couple jump scares as well as a car flipping over onto it's top.
In WCKD's labs, a young girl is seen to be screaming and writhing around from the Flare virus whilst two men hold her down and another injects her with a syringe as another two characters watches. This scene only lasts a few seconds but could be scary to some viewers.
This is the darkest film in the franchise. It also has the highest body count in all the Maze Runner films. Because of this, this film is actually much more violent than its predecessors.