CVE-2026-33429: Parse server Parse Server Has A Protected Vulnerability

MODERATE
Advisory Identifier: GHSA-qpc3-fg4j-8hgm
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CVSS 5.3
CWE-203
Published
Advisory Summary

CVE-2026-33429 is a MODERATE (CVSS 5.3) parse server has a protected vulnerability (CWE-203: Observable Discrepancy) affecting Parse server libraries in the npm ecosystem. The issue involves parse server has a protected field change detection oracle via livequery watch parameter. Remediation is available by upgrading affected packages to version 9.6.0-alpha.43, 8.6.54.

CVE-2026-33429 at a Glance

CVE Identifier CVE-2026-33429
GHSA Identifier GHSA-qpc3-fg4j-8hgm
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-203: Observable Discrepancy
Affected Product Parse server
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

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

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

How to Fix CVE-2026-33429

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.43 
npm install parse-server@9.6.0-alpha.43
parse-server fixed: 8.6.54 
npm install parse-server@8.6.54
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-2026-33429, 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.43), 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-203: Observable Discrepancy, where the product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor. 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 An attacker can subscribe to LiveQuery with a `watch` parameter targeting a protected field. Although the protected field value is properly stripped from event payloads, the presence or absence of update events reveals whether the protected field changed, creating a binary oracle. For boolean protected fields, the timing of change events is equivalent to knowing the field value. ### Patches The `watch` parameter is now validated against protected fields at subscription time, mirroring the existing validation for the `where` clause. Subscriptions that include protected fields in `watch` are rejected with a permission error. Master key connections are exempt. ### Workarounds None.

CVE-2026-33429 Affected Parse server Versions

2 component(s)
Fixed Versions:
9.6.0-alpha.438.6.54
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm/parse-server
npm
≥ 9.0.0
< 9.6.0-alpha.43
9.6.0-alpha.43
parse-server
npm/parse-server
npm
< 8.6.54
8.6.54

References

GitHub Advisory / Wiki ADVISORY
https://github.com/parse-community/parse-server/security/advisories/GHSA-qpc3-fg4j-8hgm
NVD — CVE-2026-33429 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33429
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10253
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10254
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/0c0a0a5a37ca821d2553119f2cb3be35322eda4b
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/c62eacaf38de86913f09240583448360b1cc8e67
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server

Frequently Asked Questions

What is CVE-2026-33429?
CVE-2026-33429 is a security vulnerability in Parse server involving Parse Server has a protected field change detection oracle via LiveQuery watch parameter under CWE-203: Observable Discrepancy.
Which Parse server versions are affected?
Affected versions include releases prior to 9.6.0-alpha.43, 8.6.54 across affected packages: parse-server.
What version fixes CVE-2026-33429?
Upgrading to 9.6.0-alpha.43, 8.6.54 (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.43, 8.6.54. Upgrade your dependency to 9.6.0-alpha.43, 8.6.54 or later.
What is the CVSS score of CVE-2026-33429?
CVE-2026-33429 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-33429?
CVE-2026-33429 is classified under CWE-203: Observable Discrepancy (The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.).
How can I check npm dependencies for CVE-2026-33429?
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-qpc3-fg4j-8hgm",
  "modified" : "2026-03-30T13:51:29Z",
  "published" : "2026-03-20T20:45:40Z",
  "aliases" : [ "CVE-2026-33429" ],
  "summary" : "Parse Server has a protected field change detection oracle via LiveQuery watch parameter",
  "details" : "### Impact\n\nAn attacker can subscribe to LiveQuery with a `watch` parameter targeting a protected field. Although the protected field value is properly stripped from event payloads, the presence or absence of update events reveals whether the protected field changed, creating a binary oracle. For boolean protected fields, the timing of change events is equivalent to knowing the field value.\n\n### Patches\n\nThe `watch` parameter is now validated against protected fields at subscription time, mirroring the existing validation for the `where` clause. Subscriptions that include protected fields in `watch` are rejected with a permission error. Master key connections are exempt.\n\n### Workarounds\n\nNone.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.6.0-alpha.43"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.6.54"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-qpc3-fg4j-8hgm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33429"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10253"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10254"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/0c0a0a5a37ca821d2553119f2cb3be35322eda4b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/c62eacaf38de86913f09240583448360b1cc8e67"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/parse-community/parse-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-203" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-20T20:45:40Z",
    "nvd_published_at" : "2026-03-24T19:16:53Z"
  }
}