# CVE-2026-53726: Parse Server authorization bypass in $relatedTo queries

Source: https://junglewise.ai/threats/cve-2026-53726-parse-server-authorization-bypass-in-relatedto-queries  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-12. Updated: 2026-06-19  
License: CC BY 4.0 with a link back

CVE-2026-53726 · Severity: medium · CVSS 4 · Published 2026-06-12

Parse Server is an open-source backend framework used to build and host web and mobile applications. A security flaw allowed unauthorized users to bypass privacy settings and view relationships between data objects that should have been hidden. This could lead to the exposure of sensitive information such as private group memberships, block lists, or internal account associations.

Technologies: [parse-server (npm)](https://junglewise.ai/threats/technologies/parse-server). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-53726 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-53726 being exploited in the wild.

**How severe is CVE-2026-53726?** Medium severity, with a CVSS score of 4, published 12 June 2026.

**Which products and versions are affected?** parse-server (npm) SEMVER:introduced=9.0.0,fixed=9.9.1-alpha.6.

**Is there a fix for CVE-2026-53726?** Yes. parse-server (npm): upgrade to 9.9.1-alpha.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-53726 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-53726?** Check whether you run parse-server (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- parse-server (npm): upgrade to 9.9.1-alpha.6 or later

  ```sh
  npm install parse-server@9.9.1-alpha.6
  ```


## Technical details

A vulnerability in the `$relatedTo` query operator allows for an authorization bypass (CWE-639). The root cause is that the relation query path failed to validate the caller's authentication context against the owning object's ACLs or the class's `protectedFields` before querying the join table. An unauthenticated attacker with knowledge of a target `objectId` can use this to enumerate linked objects or perform a membership oracle attack to confirm if a specific object is linked to a private parent. The issue is fixed in versions 8.6.80 and 9.9.1-alpha.6 by enforcing authorization checks on the owning object and its fields before returning results.

## Affected products

- Parse Community parse-server >= 9.0.0, < 9.9.1-alpha.6; < 8.6.80

## Identifiers

- CVE-2026-53726
- GHSA-wmwx-jr2p-4j4r

## Timeline

- 2026-06-04: disclosed: Initial disclosure to the vendor
- 2026-06-12: advisory: NVD publication date
- 2026-06-19: advisory: GitHub Advisory published

## References

- [https://api.github.com/users/offset](https://api.github.com/users/offset)
- [https://github.com/offset](https://github.com/offset)
- [https://api.github.com/users/offset/gists%7B/gist_id%7D](https://api.github.com/users/offset/gists%7B/gist_id%7D)
- [https://api.github.com/users/offset/repos](https://api.github.com/users/offset/repos)
- [https://avatars.githubusercontent.com/u/114768995?v=4](https://avatars.githubusercontent.com/u/114768995?v=4)
- [https://api.github.com/users/offset/events%7B/privacy%7D](https://api.github.com/users/offset/events%7B/privacy%7D)

## Related threats

- [Duplicate Advisory: Parse Server vulnerable to stored XSS via malformed Content-Type bypassing file upload extension blocklist](https://junglewise.ai/threats/duplicate-advisory-parse-server-vulnerable-to-stored-xss-via-malformed-00d8867c)
- [Parse Server stored XSS via malformed Content-Type bypass](https://junglewise.ai/threats/cve-2026-61448-parse-server-stored-xss-via-malformed-content-type-bypass)
- [Parse Server information disclosure in LiveQuery ACL transitions](https://junglewise.ai/threats/cve-2026-57481-parse-server-information-disclosure-in-livequery-acl-transitions)
- [Parse Community Parse Server denial of service via nested query operators](https://junglewise.ai/threats/cve-2026-57480-parse-community-parse-server-denial-of-service-via-nested-query)
- [Parse Server stored XSS via file upload extension bypass](https://junglewise.ai/threats/cve-2026-55778-parse-server-stored-xss-via-file-upload-extension-bypass)