CVE-2026-34573
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.63%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.63% probability · 50th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-407
- Affected
- parseplatform/parse-server
- Source
- security-advisories@github.com
EPSS 0.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/parse-community/parse-server/commit/ea15412795f34594cc8a674fe858d445675e0295Patch
- https://github.com/parse-community/parse-server/commit/f759bda075298ec44e2b4fb57659a0c56620483bPatch
- https://github.com/parse-community/parse-server/pull/10344Issue Tracking, Patch
- https://github.com/parse-community/parse-server/pull/10345Issue Tracking, Patch
- https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98cPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.