6.9
MEDIUM CVSS 4.0
CVE-2026-53726
Parse Server: Relation `$relatedTo` query bypasses `protectedFields` and owning-object ACL
Description

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 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. As 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. This issue has been patched in versions 8.6.80 and 9.9.1-alpha.6.

INFO

Published Date :

June 12, 2026, 7:16 p.m.

Last Modified :

June 12, 2026, 7:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-53726 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update Parse Server to patched versions to fix authorization bypass vulnerability.
  • Update Parse Server to version 8.6.80 or later.
  • Update Parse Server to version 9.9.1-alpha.6 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-53726.

URL Resource
https://github.com/parse-community/parse-server/pull/10493
https://github.com/parse-community/parse-server/pull/10494
https://github.com/parse-community/parse-server/security/advisories/GHSA-wmwx-jr2p-4j4r
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53726 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-53726 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53726 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-53726 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jun. 12, 2026

    Action Type Old Value New Value
    Added Description 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 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. As 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. This issue has been patched in versions 8.6.80 and 9.9.1-alpha.6.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-639
    Added Reference https://github.com/parse-community/parse-server/pull/10493
    Added Reference https://github.com/parse-community/parse-server/pull/10494
    Added Reference https://github.com/parse-community/parse-server/security/advisories/GHSA-wmwx-jr2p-4j4r
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.