CVE-2026-34363: Parse server LiveQuery Protected Field Leak Vulnerability

HIGH
Advisory Identifier: GHSA-m983-v2ff-wq65
CWE-362
Published
Advisory Summary

CVE-2026-34363 is a HIGH livequery protected field leak vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Parse server libraries in the npm ecosystem. The issue involves livequery protected field leak via shared mutable state across concurrent subscribers. Remediation is available by upgrading affected packages to version 9.7.0-alpha.9, 8.6.65.

CVE-2026-34363 at a Glance

CVE Identifier CVE-2026-34363
GHSA Identifier GHSA-m983-v2ff-wq65
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Parse server
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-34363

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: 9.7.0-alpha.9
npm install parse-server@9.7.0-alpha.9
parse-server fixed: 8.6.65
npm install parse-server@8.6.65
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-2026-34363, 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 9.7.0-alpha.9), 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-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. 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 When multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object. Additionally, when an afterEvent Cloud Code trigger is registered, one subscriber's trigger modifications can leak to other subscribers through the same shared mutable state. Any Parse Server deployment using LiveQuery with protected fields or afterEvent triggers is affected when multiple clients subscribe to the same class. ### Patches The fix deep-clones the shared objects at the start of each subscriber's processing callback, ensuring each subscriber works on an independent copy. Additionally, a bug was fixed where master key LiveQuery clients could not receive events on classes with protected fields due to an incorrect type passed to the sensitive data filter. ### Workarounds There is no known workaround. ### Resources - GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-m983-v2ff-wq65 - Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10330 - Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10331

CVE-2026-34363 Affected Parse server Versions

2 component(s)
Fixed Versions:
9.7.0-alpha.98.6.65
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm
≥ 9.0.0
< 9.7.0-alpha.9
9.7.0-alpha.9
parse-server
npm
< 8.6.65
8.6.65

References

Frequently Asked Questions

What is CVE-2026-34363?
CVE-2026-34363 is a security vulnerability in Parse server involving LiveQuery protected field leak via shared mutable state across concurrent subscribers under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Parse server versions are affected?
Affected versions include releases prior to 9.7.0-alpha.9, 8.6.65 across affected packages: parse-server.
What version fixes CVE-2026-34363?
Upgrading to 9.7.0-alpha.9, 8.6.65 (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 9.7.0-alpha.9, 8.6.65. Upgrade your dependency to 9.7.0-alpha.9, 8.6.65 or later.
What CWE is associated with CVE-2026-34363?
CVE-2026-34363 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check npm dependencies for CVE-2026-34363?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m983-v2ff-wq65",
  "modified" : "2026-03-31T18:51:49Z",
  "published" : "2026-03-30T17:40:59Z",
  "aliases" : [ "CVE-2026-34363" ],
  "summary" : "LiveQuery protected field leak via shared mutable state across concurrent subscribers",
  "details" : "### Impact\n\nWhen multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object.\n\nAdditionally, when an afterEvent Cloud Code trigger is registered, one subscriber's trigger modifications can leak to other subscribers through the same shared mutable state.\n\nAny Parse Server deployment using LiveQuery with protected fields or afterEvent triggers is affected when multiple clients subscribe to the same class.\n\n### Patches\n\nThe fix deep-clones the shared objects at the start of each subscriber's processing callback, ensuring each subscriber works on an independent copy. Additionally, a bug was fixed where master key LiveQuery clients could not receive events on classes with protected fields due to an incorrect type passed to the sensitive data filter.\n\n### Workarounds\n\nThere is no known workaround.\n\n### Resources\n\n- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-m983-v2ff-wq65\n- Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10330\n- Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10331",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.7.0-alpha.9"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.6.65"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-m983-v2ff-wq65"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34363"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10330"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10331"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/5834e29234593addaa0251a85f572ad4f376320b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/776c71c3078e77d38c94937f463741793609d055"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/parse-community/parse-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-30T17:40:59Z",
    "nvd_published_at" : "2026-03-31T15:16:18Z"
  }
}