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.
https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98c
https://github.com/parse-community/parse-server/pull/10345
https://github.com/parse-community/parse-server/pull/10344
https://github.com/parse-community/parse-server/commit/f759bda075298ec44e2b4fb57659a0c56620483b
https://github.com/parse-community/parse-server/commit/ea15412795f34594cc8a674fe858d445675e0295
Published: 2026-03-31
Updated: 2026-04-02
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.2
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00045