The NitroPack plugin for WordPress is vulnerable to unauthorized arbitrary transient update due to a missing capability check on the nitropack_rml_notification function in all versions up to, and including, 1.17.0. This makes it possible for authenticated attackers, with subscriber access or higher, to update arbitrary transients. Note, that these transients can only be updated to integers and not arbitrary values.
https://plugins.trac.wordpress.org/changeset/3211235/nitropack