CVE-2026-32878: Parse Server vulnerable to schema poisoning via prototype pollution in deep copy

Severity: high (CVSS 7.5 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: 2026-03-18 · updated 2026-06-17
Weakness: CWE-1321

Description

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.20 and 8.6.44, an attacker can bypass the default request keyword denylist protection and the class-level permission for adding fields by sending a crafted request that exploits prototype pollution in the deep copy mechanism. This allows injecting fields into class schemas that have field addition locked down, and can cause permanent schema type conflicts that cannot be resolved even with the master key. In 9.6.0-alpha.20 and 8.6.44, the vulnerable third-party deep copy library has been replaced with a built-in deep clone mechanism that handles prototype properties safely, allowing the existing denylist check to correctly detect and reject the prohibited keyword. No known workarounds are available.

Affected products

parse-community parse-server: before 8.6.44; from 9.0.0 before 9.6.0; 9.6.0-alpha1, 9.6.0-alpha10, 9.6.0-alpha11, 9.6.0-alpha12, 9.6.0-alpha13, 9.6.0-alpha14 (+13) — fixed in 8.6.44, 9.6.0

How to fix

Upgrade to a fixed version: parse-community parse-server 8.6.44, 9.6.0. Check the vendor advisory for mitigations.

References

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