ELI5: Explain Like I'm 5

Privilege escalation

Privilege escalation is when someone is able to use their privileges (permissions) to get extra privileges (more permissions) that they're not supposed to have. It's like if you have a key to get into your house, then you use that key to get into your neighbor's house - you didn't have permission the neighbor's house, but you used the privilege you had to get an extra privilege you weren't supposed to have.