---
title: "CVE-2026-34532: parse-server has cloud function validator bypass via prototype chain traversal"
url: https://erroneo.us/security/cve/CVE-2026-34532/
description: "CVE-2026-34532 (parse-server (npm)): Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-31
date_modified: 2026-03-31
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34532"
kev: false
cvss: 9.1
epss: 0.00486
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-34532: parse-server has cloud function validator bypass via prototype chain traversal

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 41: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 41% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes parse-server (npm) >= 9.0.0, < 9.7.0-alpha.11, fixed in 9.7.0-alpha.11 ; parse-server (npm) < 8.6.67, fixed in 8.6.67 . Check your lockfile, including transitive dependencies.

## What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.67 and 9.7.0-alpha.11, an attacker can bypass Cloud Function validator access controls by appending "prototype.constructor" to the function name in the URL. When a Cloud Function handler is declared using the function keyword and its validator is a plain object or arrow function, the trigger store traversal resolves the handler through its own prototype chain while the validator store fails to mirror this traversal, causing all access control enforcement to be skipped. This allows unauthenticated callers to invoke Cloud Functions that are meant to be protected by validators such as requireUser, requireMaster, or custom validation logic. This issue has been patched in versions 8.6.67 and 9.7.0-alpha.11.

## Affected packages

- npm `parse-server` >= 9.0.0, < 9.7.0-alpha.11 → fixed: 9.7.0-alpha.11
- npm `parse-server` < 8.6.67 → fixed: 8.6.67

## Affected products (CVE record)

- parse-community parse-server: < 8.6.67, >= 9.0.0, < 9.7.0-alpha.11

## Severity

- GitHub_M CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`
- GitHub CVSS 4.0: 9.1 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.49% probability of exploitation activity in the next 30 days; percentile 41.

## Sources

- [GitHub Advisory GHSA-vpj2-qq7w-5qq6](https://github.com/advisories/GHSA-vpj2-qq7w-5qq6)
- [CVE.org record CVE-2026-34532](https://www.cve.org/CVERecord?id=CVE-2026-34532)
- [NVD entry CVE-2026-34532](https://nvd.nist.gov/vuln/detail/CVE-2026-34532)
- [github.com](https://github.com/parse-community/parse-server/security/advisories/GHSA-vpj2-qq7w-5qq6)
- [github.com](https://github.com/parse-community/parse-server/pull/10342)
- [github.com](https://github.com/parse-community/parse-server/pull/10343)
- [github.com](https://github.com/parse-community/parse-server/commit/4fc48cf28f22eea200d74d883505f485234a48d7)
- [github.com](https://github.com/parse-community/parse-server/commit/dc59e272665644083c5b7f6862d88ce1ef0b2674)

---
Source page: https://erroneo.us/security/cve/CVE-2026-34532/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt