CVE-2026-34573

Parse Server: GraphQL complexity validator exponential fragment traversal DoS

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.

Scores

Weaknesses (CWE)

• CWE-407

Advisories

• GHSA-mfj6-6p54-m98c — parse-server has GraphQL complexity validator exponential fragment traversal DoS

European references

• ENISA EUVD · EUVD-2026-17500
• GCVE · GCVE-0-2026-34573

Affected configurations (NVD CPE)

• cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* < 8.6.68
• cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* ≥ 9.0.0 < 9.7.0
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha1:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha10:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha11:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha2:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha3:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha4:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha5:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha6:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha7:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha8:*:*:*:node.js:*:*
• cpe:2.3:a:parseplatform:parse-server:9.7.0:alpha9:*:*:*:node.js:*:*

Affected products

References

• https://github.com/parse-community/parse-server/security/advisories/GHSA-mfj6-6p54-m98c
• https://github.com/parse-community/parse-server/pull/10344
• https://github.com/parse-community/parse-server/pull/10345
• https://github.com/parse-community/parse-server/commit/ea15412795f34594cc8a674fe858d445675e0295
• https://github.com/parse-community/parse-server/commit/f759bda075298ec44e2b4fb57659a0c56620483b

Sources