Parse Server leaks protected fields via LiveQuery afterEvent trigger

Description

Impact

When a Parse.Cloud.afterLiveQueryEvent trigger is registered for a class, the LiveQuery server leaks protected fields and authData to all subscribers of that class. Fields configured as protected via Class-Level Permissions (protectedFields) are included in LiveQuery event payloads for all event types (create, update, delete, enter, leave).

Any user with sufficient CLP permissions to subscribe to the affected class can receive protected field data of other users, including sensitive personal information and OAuth tokens from third-party authentication providers.

Patches

The vulnerability was caused by a reference detachment bug. When an afterEvent trigger is registered, the LiveQuery server converts the event object to a Parse.Object for the trigger, then creates a new JSON copy via toJSONwithObjects(). The sensitive data filter was applied to the Parse.Object reference, but the unfiltered JSON copy was sent to clients. The fix ensures that the JSON copy is assigned back to the response object before filtering, so the filter operates on the actual data sent to clients.

Workarounds

Remove all Parse.Cloud.afterLiveQueryEvent trigger registrations. Without an afterEvent trigger, the reference detachment does not occur and protected fields are correctly filtered.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
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Repository advisory
Open repository advisory ↗
Source code
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Published (advisory)
2026-03-18 19:49:27 UTC
Updated
2026-03-19 21:16:05 UTC
GitHub reviewed
2026-03-18 19:49:27 UTC
NVD published
2026-03-18

EPSS Score

Score Percentile
0.03% 7.88%

CVSS Scores

Base score Version Severity Vector
8.2 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Credits

  • mtrezza (coordinator)
  • offset (reporter)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm parse-server >= 9.0.0, < 9.6.0-alpha.35 9.6.0-alpha.35
npm parse-server < 8.6.50 8.6.50

References

cvelogic Threat Intelligence