What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-10 · updated 2026-06-17
• Weakness: CWE-1321

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.

Affected products

• parse-community parse-server: before 8.6.13; from 9.0.0 before 9.5.1; 9.5.1-alpha1 — fixed in 8.6.13, 9.5.1

How to fix

Upgrade to a fixed version: parse-community parse-server 8.6.13, 9.5.1. Check the vendor advisory for mitigations.

References

• 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
• https://github.com/parse-community/parse-server/security/advisories/GHSA-5j86-7r7m-p8h6

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