Parse Server versions prior to 8.6.94 in the 8.x series and prior to 9.10.1-alpha.14 in the 9.x series allow an unauthenticated attacker who knows the public Application Id and client key to replay an introspection query that has been cached by a privileged client in Apollo Server’s persisted query cache. Because the GraphQL introspection control only applies to query text sent directly with a request and not to operations retrieved from the cache, the attacker can retrieve the full schema, including private class and field names, exposing internal data structures and potentially aiding further exploitation.

The vulnerability affects the open‑source Parse Server, published under the parse-community organization. Impacted releases are parse-server 8.2.2 up to and including 8.6.93 and parse-server 9.0.0 up to and including 9.10.0.13. Any deployment using the Apollo Server integration with automatic persisted query caching is susceptible as long as the remnants of these old versions remain in production.

With a CVSS score of 6.3, the risk is medium in the absence of additional authentication or security controls. The attack vector is unauthenticated, relying solely on knowledge of the public Application Id and client key, which are typically available to all clients. Because the exploit requires only replaying a cached query, it can be performed without network-level credentials or privileged access to the server. The vulnerability is not currently listed in CISA’s KEV catalogue and EPSS data is unavailable, but the exposure of the internal schema makes it a worthwhile target for attackers seeking to map out the data model before launching more targeted attacks. The remedy is to apply an official patch that extends introspection control to persisted queries or to remove the cached introspection query from the Apollo Server persisted query cache until the update can be applied.