Formie is a Craft CMS plugin for creating forms. Prior to 2.2.23 and 3.1.31, Formie's formie/sent-notifications/get-resend-modal-content control panel action in SentNotificationsController::actionGetResendModalContent accepts a request-supplied notification ID without permission or object-level authorization checks. Any authenticated user able to invoke the action can enumerate notification IDs and read recipient headers and complete HTML email bodies containing submitted form data, even without the sent-notification viewing permission. This issue is fixed in versions 2.2.23 and 3.1.31.
https://github.com/verbb/formie/security/advisories/GHSA-9rg8-2wvr-fgjh
https://github.com/verbb/formie/releases/tag/3.1.31
https://github.com/verbb/formie/releases/tag/2.2.23
https://github.com/verbb/formie/commit/ff81a895fa91a2e4efb8d4714501ba2d92df0b76
https://github.com/verbb/formie/commit/9f4e23c36b907ed7677563231eaba373fdb8b84b