CVE-2026-34573

Name: CVE-2026-34573
Creator: NVD / NIST
Published: 2026-03-31T16:16:33.737+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.2/10EPSS 0.46%

Last modified Jun 17, 2026

CVE-2026-34573 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. 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. EPSS estimates a 0.46% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

8.2/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.46%

36.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-407

Affected Software

Vendor	Product	Versions	Update
Parseplatform	Parse-Server	< 8.6.68	—
Parseplatform	Parse-Server	>= 9.0.0, < 9.7.0	—
Parseplatform	Parse-Server	9.7.0	Alpha1

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

Timeline

Published: Mar 31, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-34573?

How severe is CVE-2026-34573?

CVE-2026-34573 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.46% probability of exploitation in the next 30 days.

How do I fix CVE-2026-34573?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-34573?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST