{"id":"GHSA-wmwx-jr2p-4j4r","summary":"parse-server: Relation `$relatedTo` query bypasses `protectedFields` and owning-object ACL","details":"### Impact\n\nA relation query using the `$relatedTo` operator could read the membership of a `Relation` field even when that field was hidden from the requesting client by `protectedFields`, and even when the object owning the relation was not readable by the client under its ACL or class-level permissions. The request requires only the public API credentials that Parse clients normally carry — no user session, master key, or Cloud Code is needed.\n\nAs a result, an unauthenticated client who knows or obtains the owning object's `objectId` could enumerate the objects linked through a protected relation, or combine the operator with an `objectId` constraint to use it as a membership oracle — confirming whether a specific object is linked to a private parent. This affects applications that rely on `protectedFields` or object ACLs to keep `Relation` membership confidential, such as private group memberships, block lists, or account-to-resource associations.\n\n### Patches\n\nThe relation query path now authorizes `$relatedTo` against the owning object before reading the relation join table, using the caller's authentication context. The relation key is checked against the owning class's `protectedFields` (the query is rejected if the key is protected), and the owning object must be readable by the caller under its class-level permissions, ACL, and pointer permissions; otherwise the relation returns no results. Master and maintenance requests are unaffected. The check is applied consistently whether `$relatedTo` is used at the top level or nested within `$or`, `$and`, or `$nor`.\n\n### Workarounds\n\nThere is no complete workaround without upgrading. As mitigation, applications can avoid exposing sensitive membership through `Relation` fields to untrusted clients, or enforce access on the queried class in a `beforeFind` trigger.","aliases":["BIT-parse-2026-53726","CVE-2026-53726"],"modified":"2026-06-19T19:56:04.491265199Z","published":"2026-06-19T19:35:19Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-06-19T19:35:19Z","nvd_published_at":"2026-06-12T19:16:30Z","cwe_ids":["CWE-639"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/parse-community/parse-server/security/advisories/GHSA-wmwx-jr2p-4j4r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53726"},{"type":"WEB","url":"https://github.com/parse-community/parse-server/pull/10493"},{"type":"WEB","url":"https://github.com/parse-community/parse-server/pull/10494"},{"type":"PACKAGE","url":"https://github.com/parse-community/parse-server"}],"affected":[{"package":{"name":"parse-server","ecosystem":"npm","purl":"pkg:npm/parse-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"9.0.0"},{"fixed":"9.9.1-alpha.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-wmwx-jr2p-4j4r/GHSA-wmwx-jr2p-4j4r.json"}},{"package":{"name":"parse-server","ecosystem":"npm","purl":"pkg:npm/parse-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.6.80"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-wmwx-jr2p-4j4r/GHSA-wmwx-jr2p-4j4r.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"}]}