Parse Server is an open source backend server. In affected versions the Parse Cloud trigger beforeFind is not invoked in certain conditions of Parse.Query. This can pose a vulnerability for deployments where the beforeFind trigger is used as a security layer to modify the incoming query.

The vulnerability has been fixed by refactoring the internal query pipeline for a more concise code structure and implementing a patch to ensure the beforeFind trigger is invoked. This fix was introduced in commit be4c7e23c6 and has been included in releases 6.2.2 and 5.5.5. Users are advised to upgrade.

Users unable to upgrade should make use of parse server's security layers to manage access levels with Class-Level Permissions and Object-Level Access Control that should be used instead of custom security layers in Cloud Code triggers.