CVE-2026-30939
Parse Server has Denial of Service (DoS) and Cloud Function Dispatch Bypass via Prototype Chain Resolution
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, 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.
How to fix CVE-2026-30939
To remediate CVE-2026-30939, upgrade the affected package to a fixed version below.
- —upgrade to 8.6.13 or later
- —upgrade to 8.6.13 or later
Is CVE-2026-30939 being exploited?
Low — EPSS is 0.5%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 8.6.13, >= 9.0.0, < 9.5.1
- from 0, < 8.6.13
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |