CVE-2026-30938: Parse Server has denylist `requestKeywordDenylist` keyword scan bypass through nested object placement

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-10 · updated 2026-06-17
Weakness: CWE-693

Description

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.

Affected products

parse-community parse-server: before 8.6.12; from 9.0.0 before 9.5.1 — fixed in 8.6.12, 9.5.1

How to fix

Upgrade to a fixed version: parse-community parse-server 8.6.12, 9.5.1. Check the vendor advisory for mitigations.

References

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