Auth bypass in Parse-Community Parse-Server

CVE-2026-33421

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.53 and 9.6.0-alpha.42, Parse Server's LiveQuery WebSocket interface does not enforce Class-Level Permission (CLP) pointer permissions (readUserFields and pointerFields). Any authenticated user can subscribe to LiveQuery events and receive real-time updates for all objects in classes protected by pointer permissions, regardless of whether the pointer fields on those objects point to the subscribing user. This bypasses the intended read access control, allowing unauthorized access to potentially sensitive data that is correctly restricted via the REST API. This issue has been patched in versions 8.6.53 and 9.6.0-alpha.42.

Vulnerability class: Broken Access Control

EPSS: 0.004 (32.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33421?
CVE-2026-33421 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-03-24.
How severe is CVE-2026-33421?
Medium severity. CVSS v3 base score is 6.5 out of 10.