Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.12 and 9.5.1-alpha.1, the requestKeywordDenylist security control can be bypassed by placing any nested object or array before a prohibited keyword in the request payload. This is caused by a logic bug that stops scanning sibling keys after encountering the first nested value. Any custom requestKeywordDenylist entries configured by the developer are equally by-passable using the same technique. All Parse Server deployments are affected. The requestKeywordDenylist is enabled by default. This vulnerability is fixed in 8.6.12 and 9.5.1-alpha.1. Use a Cloud Code beforeSave trigger to validate incoming data for prohibited keywords across all classes.
https://github.com/parse-community/parse-server/security/advisories/GHSA-q342-9w2p-57fp
https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.1
https://github.com/parse-community/parse-server/releases/tag/8.6.12
Published: 2026-03-10
Updated: 2026-03-10
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 6.9
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium