An issue was discovered in app/Model/Attribute.php in MISP before 2.4.89. There is a critical API integrity bug, potentially allowing users to delete attributes of other events. A crafted edit for an event (without attribute UUIDs but attribute IDs set) could overwrite an existing attribute.
MISP before 2.4.81 has a potential reflected XSS in a quickDelete action that is used to delete a sighting, related to app/View/Sightings/ajax/quickDeleteConfirmationForm.ctp and app/webroot/js/misp.js.