Frappe is a full-stack web application framework. Prior to 16.23.0 and 15.112.0, Document Follow notification generation does not re-evaluate the recipient's current document permissions, allowing users whose access was revoked or reduced to continue receiving document data by email. This issue is fixed in versions 16.23.0 and 15.112.0.
https://github.com/frappe/frappe/security/advisories/GHSA-wcm9-vvcc-r8pr
https://github.com/frappe/frappe/commit/b02c1aec2c75eb0819cc6730dd230c2acb0fa60d
https://github.com/frappe/frappe/commit/0914acb998004b3878eb5cf57b765115305b49a6