CVE-2026-34573
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.
Scoring
- Severity
- HIGH
- CVSS base score
- 8.2
- CVSS 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
- EPSS probability
- 0.64%
- CWE
- CWE-407
- Published
- 2026-03-31
- Last modified
- 2026-03-31
Affected products
- parse-community parse-server
- parse-community parse-server
Weakness type
Related vulnerabilities
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- CVE-2023-54395 — PocketMine-MP before 4.12.5 Denial of Service via ModalFormResponsePacket
- CVE-2026-86435 — commonmark 1.5.0 before 2.8.4 Denial of Service via Footnote
- CVE-2026-86434 — commonmark 2.0.0 through 2.8.3 Denial of Service via Slug Collision
- CVE-2026-86433 — commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes
- CVE-2026-86430 — league/commonmark before 2.9.1 Denial of Service via parsing
- CVE-2026-86429 — commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes