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Parse Server role escalation and CLP bypass via direct `_Join` table write

Critical
mtrezza published GHSA-5f92-jrq3-28rc Mar 10, 2026

Package

npm parse-server (npm)

Affected versions

>= 9.0.0 < 9.5.2-alpha.7
< 8.6.20

Patched versions

9.5.2-alpha.7
8.6.20

Description

Impact

Parse Server's internal tables, which store Relation field mappings such as role memberships, can be directly accessed via the REST API or GraphQL API by any client using only the application key. No master key is required.

An attacker can create, read, update, or delete records in any internal relationship table. Exploiting this allows the attacker to inject themselves into any Parse Role, gaining all permissions associated with that role, including full read, write, and delete access to classes protected by role-based Class-Level Permissions (CLP). Similarly, writing to any such table that backs a Relation field used in a pointerFields CLP bypasses that access control.

Patches

The fix blocks direct client access to internal relationship tables in Parse Server's role security enforcement. All create, find, get, update, and delete operations on these tables now require the master key or maintenance key.

Workarounds

There is no known workaround.

References

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

CVE ID

CVE-2026-30966

Weaknesses

Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Learn more on MITRE.

Credits