CVE-2026-34573: Parseplatform Parse-Server

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.68 and 9.7.0-alpha.12, the GraphQL query complexity validator can be exploited to cause a denial-of-service by sending a crafted query with binary fan-out fragment spreads. A single unauthenticated request can block the Node.js event loop for seconds, denying service to all concurrent users. This only affects deployments that have enabled the requestComplexity.graphQLDepth or requestComplexity.graphQLFields configuration options. This issue has been patched in versions 8.6.68 and 9.7.0-alpha.12.

Affected products

• Parseplatform Parse-Server: before 8.6.68 (fixed in 8.6.68); from 9.0.0, before 9.7.0 (fixed in 9.7.0); version 9.7.0 only

Published 2026-03-31. Last modified 2026-07-24.