WordPress Newsletter Manager plugin <= 1.5.1 - Unauthenticated Insecure Deserialisation vulnerability

Unauthenticated Insecure Deserialisation vulnerability found by Jerome Bruander NinTechNet in WordPress Newsletter Manager plugin versions = 1.5.1. Solution 2020-12-31 - we were unable to find a patched version of this plugin. WordPress.org notification: "This plugin has been closed as of October...