CVE-2026-33508: Parse server Parse Server LiveQuery Subscription Query Vulnerability

HIGH
Advisory Identifier: GHSA-6qh5-m6g3-xhq6
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CVSS 7.5
CWE-674
Published
Advisory Summary

CVE-2026-33508 is a HIGH (CVSS 7.5) parse server livequery subscription query vulnerability (CWE-674: Uncontrolled Recursion) affecting Parse server libraries in the npm ecosystem. The issue involves parse server livequery subscription query depth bypass. Remediation is available by upgrading affected packages to version 9.6.0-alpha.45, 8.6.56.

CVE-2026-33508 at a Glance

CVE Identifier CVE-2026-33508
GHSA Identifier GHSA-6qh5-m6g3-xhq6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-674: Uncontrolled Recursion
Affected Product Parse server
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/I:N/A:H).

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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-33508

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.45 
npm install parse-server@9.6.0-alpha.45
parse-server fixed: 8.6.56 
npm install parse-server@8.6.56
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-2026-33508, 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.45), 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-674: Uncontrolled Recursion, where the product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. 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 component does not enforce the `requestComplexity.queryDepth` configuration setting when processing WebSocket subscription requests. An attacker can send a subscription with deeply nested logical operators, causing excessive recursion and CPU consumption that degrades or disrupts service availability. Deployments are affected when the LiveQuery WebSocket endpoint is reachable by untrusted clients. ### Patches The fix adds query condition depth validation to the LiveQuery subscription handler, enforcing the same `requestComplexity.queryDepth` limit that already protects REST API queries. ### Workarounds There is no known workaround other than upgrading.

CVE-2026-33508 Affected Parse server Versions

2 component(s)
Fixed Versions:
9.6.0-alpha.458.6.56
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm/parse-server
npm
≥ 9.0.0
< 9.6.0-alpha.45
9.6.0-alpha.45
parse-server
npm/parse-server
npm
< 8.6.56
8.6.56

References

GitHub Advisory / Wiki ADVISORY
https://github.com/parse-community/parse-server/security/advisories/GHSA-6qh5-m6g3-xhq6
NVD — CVE-2026-33508 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33508
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10259
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server/pull/10260
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/060d27053fb0fadf613c25aabab7fe0c82b7a899
Security Fix Commit FIX COMMIT
https://github.com/parse-community/parse-server/commit/2126fe4e12f9b399dc6b4b6a3fa70cb1825f159b
Parse server Source Repository REPOSITORY
https://github.com/parse-community/parse-server

Frequently Asked Questions

What is CVE-2026-33508?
CVE-2026-33508 is a security vulnerability in Parse server involving Parse Server LiveQuery subscription query depth bypass under CWE-674: Uncontrolled Recursion.
Which Parse server versions are affected?
Affected versions include releases prior to 9.6.0-alpha.45, 8.6.56 across affected packages: parse-server.
What version fixes CVE-2026-33508?
Upgrading to 9.6.0-alpha.45, 8.6.56 (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.45, 8.6.56. Upgrade your dependency to 9.6.0-alpha.45, 8.6.56 or later.
What is the CVSS score of CVE-2026-33508?
CVE-2026-33508 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-33508?
CVE-2026-33508 is classified under CWE-674: Uncontrolled Recursion (The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.).
How can I check npm dependencies for CVE-2026-33508?
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-6qh5-m6g3-xhq6",
  "modified" : "2026-03-30T13:51:41Z",
  "published" : "2026-03-20T21:48:17Z",
  "aliases" : [ "CVE-2026-33508" ],
  "summary" : "Parse Server LiveQuery subscription query depth bypass",
  "details" : "### Impact\n\nParse Server's LiveQuery component does not enforce the `requestComplexity.queryDepth` configuration setting when processing WebSocket subscription requests. An attacker can send a subscription with deeply nested logical operators, causing excessive recursion and CPU consumption that degrades or disrupts service availability.\n\nDeployments are affected when the LiveQuery WebSocket endpoint is reachable by untrusted clients.\n\n### Patches\n\nThe fix adds query condition depth validation to the LiveQuery subscription handler, enforcing the same `requestComplexity.queryDepth` limit that already protects REST API queries.\n\n### Workarounds\n\nThere is no known workaround other than upgrading.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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.45"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "parse-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "8.6.56"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/security/advisories/GHSA-6qh5-m6g3-xhq6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33508"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10259"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/pull/10260"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/060d27053fb0fadf613c25aabab7fe0c82b7a899"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/commit/2126fe4e12f9b399dc6b4b6a3fa70cb1825f159b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/parse-community/parse-server"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-674" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-20T21:48:17Z",
    "nvd_published_at" : "2026-03-24T19:16:54Z"
  }
}