Vulnerability in Parse-Community Parse-Server
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.
EPSS: 0.005 (37.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Parse-community Parse-server — versions < 8.6.68, >= 9.0.0, < 9.7.0-alpha.12
- Parseplatform Parse-server — versions 9.7.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-34573?
- CVE-2026-34573 is a high-severity vulnerability in Parse-Community Parse-Server, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-03-31.
- How severe is CVE-2026-34573?
- High severity. CVSS v3 base score is 7.5 out of 10.