CVE-2026-33421: Parse server Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-fph2-r4qg-9576
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CVSS 6.5
CWE-863
Published
Advisory Summary

CVE-2026-33421 is a HIGH (CVSS 6.5) remote code execution vulnerability (CWE-863: Incorrect Authorization) affecting Parse server libraries in the npm ecosystem. The issue involves parse server's livequery bypasses clp pointer permission enforcement. Remediation is available by upgrading affected packages to version 9.6.0-alpha.42, 8.6.53.

CVE-2026-33421 at a Glance

CVE Identifier CVE-2026-33421
GHSA Identifier GHSA-fph2-r4qg-9576
Severity HIGH
CVSS v3.1 Base Score 6.5
CWE Classification CWE-863: Incorrect Authorization
Affected Product Parse server
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-33421

To remediate this vulnerability, upgrade all affected Parse server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

parse-server fixed: 9.6.0-alpha.42 
npm install parse-server@9.6.0-alpha.42
parse-server fixed: 8.6.53 
npm install parse-server@8.6.53
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls parse-server

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-33421, inspect your project dependencies using npm:

npm ls parse-server

Analyze the terminal output to locate any version of Parse server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 9.6.0-alpha.42), your application is affected.

Note: The npm ls parse-server command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Parse server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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. ### Patches The LiveQuery server now enforces pointer permissions on each event. After the existing check passes (which defers pointer permissions by design), the fix checks whether any configured pointer field on the object points to the subscribing user. Events for objects that don't match are silently skipped, consistent with how ACL mismatches are handled. ### Workarounds Use ACLs on individual objects to restrict read access instead of relying solely on CLP pointer permissions. ACLs are enforced by LiveQuery.

CVE-2026-33421 Affected Parse server Versions

2 component(s)
Fixed Versions:
9.6.0-alpha.428.6.53
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm/parse-server
npm
≥ 9.0.0
< 9.6.0-alpha.42
9.6.0-alpha.42
parse-server
npm/parse-server
npm
< 8.6.53
8.6.53

References

GitHub Advisory / Wiki ADVISORY
https://github.com/parse-community/parse-server/security/advisories/GHSA-fph2-r4qg-9576
NVD — CVE-2026-33421 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33421
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10250
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10252
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/6c3317aca6eb618ac48f999021ae3ef7766ad1ea
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/976dad109f3fe3fbd0a3a35ef62e7a5d35eb0bee
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server

Frequently Asked Questions

What is CVE-2026-33421?
CVE-2026-33421 is a security vulnerability in Parse server involving Parse Server's LiveQuery bypasses CLP pointer permission enforcement under CWE-863: Incorrect Authorization.
Which Parse server versions are affected?
Affected versions include releases prior to 9.6.0-alpha.42, 8.6.53 across affected packages: parse-server.
What version fixes CVE-2026-33421?
Upgrading to 9.6.0-alpha.42, 8.6.53 (or the latest patched release for your respective branch) resolves the vulnerability.
Is parse-server affected?
Yes, parse-server is affected in releases prior to 9.6.0-alpha.42, 8.6.53. Upgrade your dependency to 9.6.0-alpha.42, 8.6.53 or later.
What is the CVSS score of CVE-2026-33421?
CVE-2026-33421 has a CVSS v3.1 base score of 6.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-33421?
CVE-2026-33421 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check npm dependencies for CVE-2026-33421?
Run the dependency tree command: 'npm ls parse-server'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-fph2-r4qg-9576",
  "modified" : "2026-03-30T13:51:19Z",
  "published" : "2026-03-20T20:44:36Z",
  "aliases" : [ "CVE-2026-33421" ],
  "summary" : "Parse Server's LiveQuery bypasses CLP pointer permission enforcement",
  "details" : "### Impact\n\nParse 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.\n\n### Patches\n\nThe LiveQuery server now enforces pointer permissions on each event. After the existing check passes (which defers pointer permissions by design), the fix checks whether any configured pointer field on the object points to the subscribing user. Events for objects that don't match are silently skipped, consistent with how ACL mismatches are handled.\n\n### Workarounds\n\nUse ACLs on individual objects to restrict read access instead of relying solely on CLP pointer permissions. ACLs are enforced by LiveQuery.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
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      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.6.0-alpha.42"
      } ]
    } ]
  }, {
    "package" : {
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      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-fph2-r4qg-9576"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33421"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10250"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10252"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/6c3317aca6eb618ac48f999021ae3ef7766ad1ea"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/976dad109f3fe3fbd0a3a35ef62e7a5d35eb0bee"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/parse-community/parse-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-20T20:44:36Z",
    "nvd_published_at" : "2026-03-24T19:16:53Z"
  }
}