CVE-2026-53726 Parse Server: Relation `$relatedTo` query bypasses `protectedFields` and owning-object ACL

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.80 and 9.9.1-alpha.6, a relation query using the $relatedTo operator could read the membership of a Relation field even when that field was hidden from the requesting clie...