Parse Server has a LiveQuery protected-field guard bypass via array-like logical operator value

CVE-2026-34595 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

An authenticated user with find class-level permission can bypass the protectedFields class-level permission setting on LiveQuery subscriptions. By sending a subscription with a $or, $and, or $nor operator value as a plain object with numeric keys and a length property (an "array-like" object) instead of an array, the protected-field guard is bypassed. The subscription event firing acts as a binary oracle, allowing the attacker to infer whether a protected field matches a given test value.

Patches

The fix validates that $or, $and, and $nor operator values are arrays in the LiveQuery subscription handler, the query depth checker, and the protected-field guard. As defense in depth, the LiveQuery query evaluator also rejects non-array values for these operators.

Workarounds

There is no known workaround.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-04-01 00:07:39 UTC
Updated
2026-04-01 00:07:41 UTC
GitHub reviewed
2026-04-01 00:07:39 UTC
NVD published
2026-03-31

EPSS Score

Score Percentile
0.03% 8.57%

CVSS Scores

Base score Version Severity Vector
5.3 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/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:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:L)
Limited 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

Type Value
GHSA GHSA-mmg8-87c5-jrc2 ↗
CVE CVE-2026-34595 ↗

CWEs

CWE id Name
CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')

Credits

  • bugbunny-research (reporter)
  • mtrezza (coordinator)

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, < 9.7.0-alpha.16 9.7.0-alpha.16 —
npm parse-server < 8.6.70 8.6.70 —

References

cvelogic Threat Intelligence