The Advanced Custom Fields (ACF) Free and Pro WordPress plugins 6.x before 6.1.0 and 5.x before 5.12.5 unserialize user controllable data, which could allow users with a role of Contributor and above to perform PHP Object Injection when a suitable gadget is present.
https://wpscan.com/vulnerability/cf376ca2-92f6-44ff-929a-ace809460a33
https://wpscan.com/vulnerability/8e5ec88e-0e66-44e4-bbf2-74155d849ede