---
id: "CVE-2026-121965"
kind: "vulnerability"
aliases: ["CVE-2026-121965"]
title: "Parse Server: prototype pollution lets a client break built-in functions"
severity: "medium"
cvss: 6.0
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["backend-as-a-service", "node.js", "package", "parse-server", "self-hosted"]
not_affected_if: ["livequery-disabled", "no-cloud-code-triggers"]
published_at: "2026-11-04T16:17:49+00:00"
first_seen_at: "2026-11-04T16:28:15+00:00"
updated_at: "2026-11-04T16:28:59+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121965", "first_seen_at": "2026-11-04T16:28:15+00:00"}]
---

# Parse Server: prototype pollution lets a client break built-in functions

Parse Server builds objects for Cloud Code triggers and LiveQuery in a way that lets a dot-notation key write onto a process-wide built-in. A client with write access to an object in a class with a trigger or LiveQuery can corrupt that built-in, causing unrelated requests to fail until restart.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Parse Server version with `npm ls parse-server` or the `version` field in its package.json.
- Look for Cloud Code triggers or LiveQuery enabled on any class your clients can write to.

## Fix

- Parse Server 8.x: move to `8.6.113` or later.
- Parse Server 9.x: move to `9.10.6-alpha.5` or later (9.0.0 is affected).

## Timeline

- 2026-11-04T16:28:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121965

## Documents

- [advisory] Vendor advisory: github.com https://github.com/parse-community/parse-server/security/advisories/GHSA-95hp-82c6-25q5
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/parse-server-before-8.6.113-and-9.10.6-alpha.5-prototype-pollution-via-dot-notation-key

## From the sources

Parse Server before 8.6.113 and 9.0.0 before 9.10.6-alpha.5 contains a prototype pollution vulnerability when building objects for Cloud Code triggers and LiveQuery, where a dot notation key whose intermediate segment resolves through an inherited member writes onto a process-wide built-in. Clients with write access to an object in a class with a trigger or LiveQuery can corrupt a built-in function, making unrelated requests fail until restart and denying service to all clients and hosted applications.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_