CVE-2026-33163

The record

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.35 and 8.6.50, when a `Parse.Cloud.afterLiveQueryEvent` trigger is registered for a class, the LiveQuery server leaks protected fields and `authData` to all subscribers of that class. Fields configured as protected via Class-Level Permissions (`protectedFields`) are included in LiveQuery event payloads for all event types (create, update, delete, enter, leave). Any user with sufficient CLP permissions to subscribe to the affected class can receive protected field data of other users, including sensitive personal information and OAuth tokens from third-party authentication providers. The vulnerability was caused by a reference detachment bug. When an `afterEvent` trigger is registered, the LiveQuery server converts the event object to a `Parse.Object` for the trigger, then creates a new JSON copy via `toJSONwithObjects()`. The sensitive data filter was applied to the `Parse.Object` reference, but the unfiltered JSON copy was sent to clients. The fix in versions 9.6.0-alpha.35 and 8.6.50 ensures that the JSON copy is assigned back to the response object before filtering, so the filter operates on the actual data sent to clients. As a workaround, remove all `Parse.Cloud.afterLiveQueryEvent` trigger registrations. Without an `afterEvent` trigger, the reference detachment does not occur and protected fields are correctly filtered.

Affected packages

Related vulnerabilities

• GHSA-5hmj-jcgp-6hff Parse Server leaks protected fields via LiveQuery afterEvent trigger Same vulnerability
• GHSA-97pr-9hgg-3p8r parse-server: LiveQuery discloses object data to a subscriber across an ACL read-access… Also affects parse-server
• GHSA-wmwx-jr2p-4j4r parse-server: Relation `$relatedTo` query bypasses `protectedFields` and owning-object ACL Also affects parse-server
• GHSA-7wqv-xjf3-x35v parse-server: Stored XSS via trailing-dot filename bypassing file upload extension… Also affects parse-server
• GHSA-p84r-h6rx-f2xr parse-server: Server option routeAllowList is bypassable through batch sub-requests Also affects parse-server
• GHSA-cgxm-vr2f-6fj8 parse-server: Denial of service via exponential-time processing of deeply nested query… Also affects parse-server
• CVE-2026-53726 Parse Server is an open source backend that can be deployed to any infrastructure that… Also affects parse-server
• CVE-2026-53724 Parse Server is an open source backend that can be deployed to any infrastructure that… Also affects parse-server