Prototype Pollution in Parse-Community Parse-Server
CVE-2026-30939
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.
Vulnerability class: Prototype Pollution
EPSS: 0.005 (39.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Parse-community Parse-server — versions < 8.6.13, >= 9.0.0 < 9.5.1-alpha.2
- Parseplatform Parse-server — versions 9.5.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Mitigation, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-30939?
- CVE-2026-30939 is a high-severity vulnerability in Parse-Community Parse-Server, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.5/10. Published 2026-03-10.
- How severe is CVE-2026-30939?
- High severity. CVSS v3 base score is 7.5 out of 10.