Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.6.0-alpha.21 and 8.6.45, an unauthenticated attacker can crash the Parse Server process by sending a single request with deeply nested query condition operators. This terminates the server and denies service to all connected clients. Starting in version 9.6.0-alpha.21 and 8.6.45, a depth limit for query condition operator nesting has been added via the `requestComplexity.queryDepth` server option. The option is disabled by default to avoid a breaking change. To mitigate, upgrade and set the option to a value appropriate for your app. No known workarounds are available.
https://github.com/parse-community/parse-server/security/advisories/GHSA-9xp9-j92r-p88v
Published: 2026-03-18
Updated: 2026-03-19
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00046